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  <xs:element id="fsbc_SubordinatedNotesMaturityDateOfSeptember152027Member" abstract="true" name="SubordinatedNotesMaturityDateOfSeptember152027Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_NumberOfBorrowingRelationshipsSubjectToDefermentCARESAct" abstract="false" name="NumberOfBorrowingRelationshipsSubjectToDefermentCARESAct" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fsbc_CommercialConstructionLoansMember" abstract="false" name="CommercialConstructionLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_CCorpConversionFederalRateChange" abstract="false" name="CCorpConversionFederalRateChange" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_FederalReserveBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged" abstract="false" name="FederalReserveBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_UnvestedRestrictedShares" abstract="false" name="UnvestedRestrictedShares" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="fsbc_CashAndCashEquivalentsLessTimeDepositsAtCarryingValue" abstract="false" name="CashAndCashEquivalentsLessTimeDepositsAtCarryingValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_FinancialAssetsRecordedAtAmortizedCostAbstract" abstract="true" name="FinancialAssetsRecordedAtAmortizedCostAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fsbc_InterestExpenseDomesticDepositLiabilitiesTimeDeposit250000Minimum" abstract="false" name="InterestExpenseDomesticDepositLiabilitiesTimeDeposit250000Minimum" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_UndisbursedCommercialRealEstateLoansMember" abstract="false" name="UndisbursedCommercialRealEstateLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_LoanRelatedFees" abstract="false" name="LoanRelatedFees" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_PercentageOfLargestSingleDepositToDeposits" abstract="false" name="PercentageOfLargestSingleDepositToDeposits" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="fsbc_WatchMember" abstract="false" name="WatchMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_NumberOfBoardDirectors" abstract="false" name="NumberOfBoardDirectors" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fsbc_Deposits5MillionOrMoreNumberOfDepositRelationships" abstract="false" name="Deposits5MillionOrMoreNumberOfDepositRelationships" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fsbc_RealEstateRelatedLoansPercentage" abstract="false" name="RealEstateRelatedLoansPercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="fsbc_NumberOfCorrespondentBanks" abstract="false" name="NumberOfCorrespondentBanks" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fsbc_BenefitOfSCorporationStatus" abstract="false" name="BenefitOfSCorporationStatus" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_LoanRelatedExpenses" abstract="false" name="LoanRelatedExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_APICShareBasedPaymentArrangementIncreaseForCostRecognitionInShares" abstract="false" name="APICShareBasedPaymentArrangementIncreaseForCostRecognitionInShares" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="fsbc_DisclosureInterestbearingDepositsAbstract" abstract="true" name="DisclosureInterestbearingDepositsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fsbc_CommonStockConvertibleSharesIssuable" abstract="false" name="CommonStockConvertibleSharesIssuable" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="fsbc_CommercialLinesOfCreditMember" abstract="false" name="CommercialLinesOfCreditMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_FixedToFloatingRateSubordinatedNotesIssuedSep2017Member" abstract="true" name="FixedToFloatingRateSubordinatedNotesIssuedSep2017Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_NumberOfShareholders" abstract="false" name="NumberOfShareholders" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fsbc_OtherCommitmentsMember" abstract="false" name="OtherCommitmentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_NumberOfLoansSubjectToDefermentCARESAct" abstract="false" name="NumberOfLoansSubjectToDefermentCARESAct" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fsbc_HeldToMaturitySecuritiesGrossUnrealizedLoss" abstract="false" name="HeldToMaturitySecuritiesGrossUnrealizedLoss" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fsbc_SecureLocalAgencyDepositMember" abstract="true" name="SecureLocalAgencyDepositMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_InterestExpenseRecognizedOnInterestBearingDepositsTableTextBlock" abstract="false" name="InterestExpenseRecognizedOnInterestBearingDepositsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fsbc_UndisbursedConstructionLoansMember" abstract="false" name="UndisbursedConstructionLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fsbc_NumberOfUnsecuredFederalFunds" abstract="false" name="NumberOfUnsecuredFederalFunds" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fsbc_FinancialLiabilitiesRecordedAtAmortizedCostAbstract" abstract="true" name="FinancialLiabilitiesRecordedAtAmortizedCostAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
</xs:schema>
