If the Builder::XChar module is not currently defined, fail on any name clashes in standard library classes.

Namespace
Methods
C
Class Public methods
check_for_name_collision(klass, method_name, defined_constant=nil)

Source: show 

# File rails/activesupport/lib/active_support/vendor/builder/xchar.rb, line 12
def self.check_for_name_collision(klass, method_name, defined_constant=nil)
  if klass.instance_methods.include?(method_name)
    fail RuntimeError,
      "Name Collision: Method '#{method_name}' is already defined in #{klass}"
  end
end