class Builder:
def set_a(self, a):
self.a = a
return self
def set_b(self, b):
self.b = b
return self
def set_c(self, c):
self.c = c
return self
def set_d(self, d):
self.d = d
return self
def set_e(self, e):
self.d = d
return self
Builder().set_a('a1').set_b('b2').set_c('c3').set_d('d4').set_e('e4')
# ^ defined: 2
# ^ defined: 6
# ^ defined: 10
# ^ defined: 14
# ^ defined: 18