boolean () { SyntaxTreeBuilder.Marker withItem = myBuilder.mark(); if (!getExpressionParser().parseSingleExpression(false)) { withItem.drop(); return false; } if (matchToken(PyTokenTypes.AS_KEYWORD)) { if (!getExpressionParser().parseSingleExpression(true)) { myBuilder.error(PyParsingBundle.message("PARSE.expected.identifier")); } } withItem.done(PyElementTypes.WITH_ITEM); return true; }