docs: def scheme_specification(cls):
  		""" :meth:`.WSchemeHandler.scheme_specification` method implementation
  		"""
  		return WSchemeSpecification(
  			'ftp',
  			WURIComponentVerifier(WURI.Component.username, WURIComponentVerifier.Requirement.optional),
  			WURIComponentVerifier(WURI.Component.password, WURIComponentVerifier.Requirement.optional),
  			WURIComponentVerifier(WURI.Component.hostname, WURIComponentVerifier.Requirement.required),
  			WURIComponentVerifier(WURI.Component.path, WURIComponentVerifier.Requirement.optional)
  		)