class_docstr: Transforms an input to upper and lower case or capitalize case.
  A sentence can only be transformed into one sentence of each case at most.
code: def case_trans(text, case_type):
      if case_type == "upper":
          transform_text = text.upper()
      elif case_type == "lower":
          transform_text = text.lower()
      else:
          transform_text = text.title()
  
      return transform_text
  
file_path: textflint/textflint/generation/transformation/UT/word_case.py
imports: import random
  from ..transformation import Transformation
label_desc: Use image node_id 4 for calling the WordCase obj's underlying member method code with example usage: obj.case_trans(text, case_type) and returns: transform_text