code: def find(lst, a, case_sensitive=True):
      
      a = force_list(a)
  
      if not case_sensitive:
          lst = [x.lower() for x in lst]
          a = [y.lower() for y in a]
  
      return [i for i, x in enumerate(lst) if x in a]
docs: Return indices of a list which have elements that match an object or list of objects
  
      Args:
          lst: list of values
          a: object(s) to check equality
          case_sensitive: if the search should be case sensitive
  
      Returns:
          list: list of indicies of lst which equal a