from cyclic import Cyclic

cy = Cyclic()

# Let's say A is a prent of B
cy.add(B, A)

# B is a parent of C
cy.add(C, B)

# C is a parent of A (cyclic)
cy.add(A, C)

# let's see if C is in any kind of cyclic relation

print(cy.is_cyclic(C)) # True