code: def to_value(original_string, corenlp_value=None):
      
      if isinstance(original_string, Value):
          # Already a Value
          return original_string
      if not corenlp_value:
          corenlp_value = original_string
      # Number?
      amount = NumberValue.parse(corenlp_value)
      if amount is not None:
          return NumberValue(amount, original_string)
      # Date?
      ymd = DateValue.parse(corenlp_value)
      if ymd is not None:
          if ymd[1] == ymd[2] == -1:
              return NumberValue(ymd[0], original_string)
          else:
              return DateValue(ymd[0], ymd[1], ymd[2], original_string)
      # String.
      return StringValue(original_string)
docs: Convert the string to Value object.
  
      Args:
          original_string (basestring): Original string
          corenlp_value (basestring): Optional value returned from CoreNLP
      Returns:
          Value