Returns the relation type name.

  Returns the relation type name.
Returns: the relation type name.

  Returns the role info (RoleInfo object) for the given role info name (null if not found).

  Returns the role info (RoleInfo object) for the given role info name
(null if not found).
Returns: RoleInfo object providing role definition does not exist
Parameters:
- roleInfoName - role info name
Throws:
- IllegalArgumentException - if null parameter
- RoleInfoNotFoundException - if no role info with that name in relation type.

  Returns the list of role definitions (ArrayList of RoleInfo objects).

  Returns the list of role definitions (ArrayList of RoleInfo objects).
Returns: an {@link ArrayList} of {@link RoleInfo}.