[Python] helper_predicates module on Python not found

I just had a course where my teacher used this code, so I copied it to try it on PyCharm Community Edition and it says unresolved reference for helper_predicates, is_sorted, all_lte_all, and is_permutation. When he used this code in class it worked perfectly, can someone explain if helper_predicates exists as a built-in module or if I have to install something?

from helper_predicates import *
import random

def lusinvariant(values, orig_values, i):
return is_sorted(values[:i]) and \
is_permutation(values, orig_values) and \
all_lte_all(values[:i], values[i:])

def minimum_position(values, start):
minPos = start
i = start + 1

assert lte_all(values[minPos], values[start:i])
while i != len(values):
assert lte_all(values[minPos], values[start:i])

if values < values[minPos]:
minPos = i

i += 1
assert lte_all(values[minPos], values[start:i])
assert lte_all(values[minPos], values[start:i])
return minPos


# Hint: def selection_sort_recursive(values, start)
def selection_sort(values):
orig_values = values[:] # enkel nodig voor lusinvariant
i = 0

assert lusinvariant(values, orig_values, i)
while i != len(values):
assert lusinvariant(values, orig_values, i)

minPos = minimum_position(values, i)
values, values[minPos] = values[minPos], values

i += 1
assert lusinvariant(values, orig_values, i)

assert lusinvariant(values, orig_values, i)

# Test
lst = list(range(20))
random.shuffle(lst)
print(lst)

print("Iteratief:")
# Hint: selection_sort_recursive(kopie, 0)
selection_sort(lst)
print(lst)

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