public boolean parseYieldOrTupleExpression(final boolean isTargetExpression) {
    if (myBuilder.getTokenType() == PyTokenTypes.YIELD_KEYWORD) {
      SyntaxTreeBuilder.Marker yieldExpr = myBuilder.mark();
      myBuilder.advanceLexer();
      if (myBuilder.getTokenType() == PyTokenTypes.FROM_KEYWORD) {
        myBuilder.advanceLexer();
        final boolean parsed = parseTupleExpression(false, isTargetExpression, false);
        if (!parsed) {
          myBuilder.error(message("PARSE.expected.expression"));
        }
        yieldExpr.done(PyElementTypes.YIELD_EXPRESSION);
        return parsed;
      }
      else {
        parseTupleExpression(false, isTargetExpression, false);
        yieldExpr.done(PyElementTypes.YIELD_EXPRESSION);
        return true;
      }
    }
    else {
      return parseTupleExpression(false, isTargetExpression, false);
    }
  }
public boolean parseYieldOrTupleExpression(final boolean isTargetExpression)