Given a parameter name, a possibly-null default value, and a collection companion object, attempts to extract all the parameter values and return a collection instance.
Given a parameter name and a possibly-null default value, attempts to extract the first parameter values and return a Some instance, returning the default value if no parameter exists.
Given a parameter name and a possibly-null default value, attempts to extract the first parameter values and return a Some instance, returning the default value if no parameter exists. If defaultValue is null and no parameter exists, returns None.
Given a parameter name, a possibly-null default value, and a collection companion object, attempts to extract all the parameter values and return a collection instance. If defaultValue is null and no parameter exists, returns an empty collection.