code: def assert_string(**kwargs):
      for label, subject in kwargs.items():
          if not isinstance(subject, string_type):
              fmt = "{0} must be a string, not {1}"
              msg = fmt.format(label, repr(subject))
              raise TypeError(msg)
  
file_path: wand/wand/assertions.py
imports: import numbers
  from .compat import string_type
  from .color import Color
label_desc: Use image node_id 8 for calling a global function with example usage: assert_string() without return types