The method is intended for instantiation of meta-classes with just one attribute. For example, all the metaclasses representing literals in a grammar (NumberLiteral, StringLiteral).

I used to have a method that either would take a map or a single value. In the map case it would instantiate the metaclass and then assign all the fields, in the case of the single value the object is expected to have exactly one attribute: the value passed to the method is assigned to the only attribute. If there are two attributes I don't know to which attribute to assign the value.

I removed the logic to manage the map value because Martin told me it was already implemented.