class Thor::Task

def run(instance, args=[])

implementation to create custom tasks.
By default, a task invokes a method in the thor class. You can change this 
def run(instance, args=[])
  raise UndefinedTaskError, "the '#{name}' task of #{instance.class} is private" unless public_method?(instance)
  instance.send(name, *args)
rescue ArgumentError => e
  raise e if instance.class.respond_to?(:debugging) && instance.class.debugging
  parse_argument_error(instance, e, caller)
rescue NoMethodError => e
  raise e if instance.class.respond_to?(:debugging) && instance.class.debugging
  parse_no_method_error(instance, e)
end