code: def apply_types(use_types, guess_type, line):
      
      new_line = {}
      for k, v in line.items():
          if use_types.has_key(k):
              new_line[k] = force_type(use_types[k], v)
          elif guess_type:
              new_line[k] = determine_type(v)
          else:
              new_line[k] = v
      return new_line
docs: Apply the types on the elements of the line