Any function object that is a class attribute defines a method for instances of that class. It is not necessary that the function definition is textually enclosed in the class definition: assigning a function object to a local variable in the class is also ok.
Most children are born with very little arch in the feet. As they grow and walk, the soft tissues along the bottom of the feet tighten, which gradually shapes the arches of the feet. Children with flexible flatfoot often do not begin to develop an arch until the age of 5 years or older. Some children never develop an arch. If flexible flatfoot continues into adolescence, a child may experience aching pain along the bottom of the foot. A doctor should be consulted if a child's flatfeet cause pain.
Leg bones usually continue to grow straighter until the child is 6 to 8 years old. Internal tibial torsion is present if the lower leg remains turned in. When the child begins walking, the feet turn inward because the tibia in the lower leg, just above the foot, points the foot inward. As the tibia becomes longer, it usually untwists. The most common overall cause of in-toeing is internal tibial torsion.