A normal module, like NormalClass

Methods
D
M
S
Instance Public methods
definition()

The definition of this module, module MyModuleName

Source: show | on GitHub 

# File ../ruby/lib/rdoc/normal_module.rb, line 18
def definition
  "module #{full_name}"
end
module?()

This is a module, returns true

Source: show | on GitHub 

# File ../ruby/lib/rdoc/normal_module.rb, line 25
def module?
  true
end
superclass()

Modules don't have one, raises NoMethodError

Source: show | on GitHub 

# File ../ruby/lib/rdoc/normal_module.rb, line 61
def superclass
  raise NoMethodError, "#{full_name} is a module"
end