Implement the support for variable custom types as defined in the specification. A variable custom type provides behaviour to allow the use of specific pre-determined variable types.
An example use case would be a variable type for an Amazon EC2 instance size which only allows a fixed set of options as valid values.
A custom variable type should have an interface which allows looking up options for a custom type that is used for validation and lookup tooling.
Implement the support for variable custom types as defined in the specification. A variable custom type provides behaviour to allow the use of specific pre-determined variable types.
An example use case would be a variable type for an Amazon EC2 instance size which only allows a fixed set of options as valid values.
A custom variable type should have an interface which allows looking up options for a custom type that is used for validation and lookup tooling.