question: private void validateVcenterCredentials ( VcenterParam param , Vcenter vcenter ) { if ( StringUtils . isBlank ( param . getPassword ( ) ) && vcenter != null ) { param . setPassword ( StringUtils . trimToNull ( vcenter . getPassword ( ) ) ) ; } if ( StringUtils . isBlank ( param . getUserName ( ) ) && vcenter != null ) { param . setUserName ( StringUtils . trimToNull ( vcenter . getUsername ( ) ) ) ; } ArgValidator . checkFieldNotNull ( param . getUserName ( ) , "username" ) ; ArgValidator . checkFieldNotNull ( param . getPassword ( ) , "password" ) ; }
target:  Validates vCenter user credentials from create or update parameters.