code: def label_context(label_info, multi_line=True, sep=': '):
      
      if len(label_info) == 1:
          return label_value(label_info, multi_line)
      else:
          return label_both(label_info, multi_line, sep)
docs: Create an unabiguous label string
  
      If facetting over a single variable, `label_value` is
      used, if two or more variables then `label_both` is used.
  
      Parameters
      ----------
      label_info : series
          Series whose values will be returned. It must have
          an index made of variable names
      multi_line : bool
          Whether to place each variable on a separate line
      sep :  str
          Separation between variable name and value
  
      Returns
      -------
      out : str
          Contatenated label values (or pairs of variable names
          & values)