code: def visit_FunctionBody(self, node):
          
          for child in node.children:
              return_value = self.visit(child)
  
              if isinstance(child, ReturnStatement):
                  return return_value
  
              if isinstance(child, (IfStatement, WhileStatement)):
                  if return_value is not None:
                      return return_value
  
          return NoneType()
docs: Visitor for `FunctionBody` AST node.