question: private void validatePrivateElement ( String localName , boolean startElement ) { if ( ! startElement ) { if ( inMaskAfterPrivateElement && localName . equals ( FXGConstants . FXG_MASK_ELEMENT ) ) inMaskAfterPrivateElement = false ; return ; } if ( localName . equals ( FXGConstants . FXG_PRIVATE_ELEMENT ) ) { if ( seenPrivateElement ) { throw new FXGException ( "PrivateElementMultipleOccurrences" , startLine , startColumn ) ; } else { if ( ( ! inSkippedElement ( ) ) && stack . size ( ) == 1 ) seenPrivateElement = true ; else throw new FXGException ( "PrivateElementNotChildOfGraphic" , startLine , startColumn ) ; } } else { if ( seenPrivateElement && ( ! inSkippedElement ( ) ) ) { if ( ( ! inMaskAfterPrivateElement ) && ( localName . equals ( FXGConstants . FXG_MASK_ELEMENT ) ) ) { inMaskAfterPrivateElement = true ; } else { if ( ! inMaskAfterPrivateElement ) throw new FXGException ( "PrivateElementNotLast" , startLine , startColumn ) ; } } } }
target:  validates restrictions on PRIVATE element