@Override public void visitExpression(@NotNull PsiExpression expression) {
    startElement(expression);
    DfaValue dfaValue = JavaDfaValueFactory.getExpressionDfaValue(myFactory, expression);
    push(dfaValue == null ? myFactory.getUnknown() : dfaValue, expression);
    finishElement(expression);
  }
@Override public void visitExpression(@NotNull PsiExpression expression)