code: private Node tryFoldKnownNumericMethods(Node subtree, Node callTarget) {
      checkArgument(subtree.isCall());
  
      if (isASTNormalized()) {
        // check if this is a call on a string method
        // then dispatch to specific folding method.
        String functionNameString = callTarget.getString();
        Node firstArgument = callTarget.getNext();
        if ((firstArgument != null) && (firstArgument.isString() || firstArgument.isNumber())
            && (functionNameString.equals("parseInt") || functionNameString.equals("parseFloat"))) {
          subtree = tryFoldParseNumber(subtree, functionNameString, firstArgument);
        }
      }
      return subtree;
    }
docs: Try to evaluate known Numeric methods
  parseInt(), parseFloat()