question: @ Override public int hashCode ( ) { int code = 0 ; if ( fPublicId != null ) { code += fPublicId . hashCode ( ) ; } if ( fLiteralSystemId != null ) { code += fLiteralSystemId . hashCode ( ) ; } if ( fBaseSystemId != null ) { code += fBaseSystemId . hashCode ( ) ; } if ( fExpandedSystemId != null ) { code += fExpandedSystemId . hashCode ( ) ; } if ( fNamespace != null ) { code += fNamespace . hashCode ( ) ; } return code ; }
target:  Returns a hash code for this object.