in doubles/call_count_accumulator.py [0:0]
def error_string(self):
"""Returns a well formed error message
e.g at least 5 times but was called 4 times
:rtype string
"""
if self.has_correct_call_count():
return ''
return '{} instead of {} {} '.format(
self._restriction_string(),
self.count,
pluralize('time', self.count)
)