class Rails::Generators::Base

def class_collisions(*class_names)
  return unless behavior == :invoke
  return if options.skip_collision_check?
  return if options.force?
  class_names.flatten.each do |class_name|
    class_name = class_name.to_s
    next if class_name.strip.empty?
    # Split the class from its module nesting
    nesting = class_name.split("::")
    last_name = nesting.pop
    last = extract_last_module(nesting)
    if last && last.const_defined?(last_name.camelize, false)
      raise Error, "The name '#{class_name}' is either already used in your application " \
                   "or reserved by Ruby on Rails. Please choose an alternative or use --skip-collision-check "  \
                   "or --force to skip this check and run this generator again."
    end
  end
end