<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def enum_from_yaml(cls: Type[T_EnumFromYAML], constructor: Constructor, node: ruamel.yaml.nodes.ScalarNode) -> T_EnumFromYAML: """ Decode YAML representation. This is a mixin method for reading enum values from YAML. It needs to be added to the enum as a classmethod. See the module docstring for further information on this approach and how to implement it. Note: This method assumes that the name of the enumeration value was stored as a scalar node. Args: constructor: Constructor from the YAML object. node: Scalar node extracted from the YAML being read. Returns: The constructed YAML value from the name of the enumerated value. """

    # mypy doesn't like indexing to construct the enumeration.
    return cls[node.value]