RT::CustomFieldValues::External - Pull possible values for a custom field from an arbitrary external data source.
Custom field value lists can be produced by creating a class that inherits from
RT::CustomFieldValues::External, and overloading
ExternalValues. See RT::CustomFieldValues::Groups for a simple example.
Subclasses should implement the following methods:
This method should return a string describing the data source; this is the identifier by which the user will see the dropdown.
This method should return an array reference of hash references. The hash references should contain keys for