Before this commit:

  mruby -e 'CRubyExtension.ruby_method' # => A Ruby Extension
  mruby -e 'CRubyExtension.c_method'    # => A C Extension
  mruby -e 'CExtension.c_method'        # => A C Extension
  mruby -e 'RubyExtension.ruby_method'  # => A Ruby Extension

After this commit:

  mruby -e 'CRubyExtension.ruby_method' # => CRubyExtension: A Ruby Extension
  mruby -e 'CRubyExtension.c_method'    # => CRubyExtension: A C Extension
  mruby -e 'CExtension.c_method'        # => CExtension: A C Extension
  mruby -e 'RubyExtension.ruby_method'  # => RubyExtension: A Ruby Extension