class_docstr: For the word (ie, node) of a dependency tree and its attributes. Inherits
  from the ``Element`` class of Python's ``xml.etree`` library.
  
  >>> desc_form = Form('described')
  >>> desc_form
  described_0
  >>> desc_form.set('Tense', 'Past')
  >>> desc_form
  described_0
  >>> desc_form / 'VBN'
  described_0/VBN
  >>> desc_form.full_str()
  'described_0 [Tense=Past,pos=VBN]'
code: def __str__(self) -> str:
      return (
          self.tag
          + "_"
          + self("form_id")
          + (("/" + self("pos")) if self("pos") else "")
      )
  
imports: from typing import Dict, List, Union
  from xml.etree.ElementTree import Element, ElementTree
  from cltk.core.data_types import Doc, Process, Word
  from cltk.core.exceptions import CLTKException
  from cltk.morphology.universal_dependencies_features import NOMINAL_FEATURES, OTHER_FEATURES, VERBAL_FEATURES, MorphosyntacticFeature
label_desc: Use image node_id 5 for calling the Form obj's underlying member method code with example usage: obj.__str__() and returns: unknown