docs: def invert_map(map):
  	"""
  	Given a dictionary, return another dictionary with keys and values
  	switched. If any of the values resolve to the same key, raises
  	a ValueError.
  
  	>>> numbers = dict(a=1, b=2, c=3)
  	>>> letters = invert_map(numbers)
  	>>> letters[1]
  	'a'
  	>>> numbers['d'] = 3
  	>>> invert_map(numbers)
  	Traceback (most recent call last):
  	...
  	ValueError: Key conflict in inverted mapping
  	"""
  	res = dict((v, k) for k, v in map.items())
  	if not len(res) == len(map):
  		raise ValueError('Key conflict in inverted mapping')
  	return res