code: @Override
  	public void deleteRole(String rolename) throws RolesException {
  		if (role_list.containsKey(rolename)) {
  			List<String> users_with_role = role_list.get(rolename);
  			for (String user : users_with_role) {
  				// Remove the role from this user
  				List<String> roles_of_user = user_list.get(user);
  				roles_of_user.remove(rolename);
  				user_list.put(user, roles_of_user);
  
  				// Update our file_store
  				String roles = StringUtils.join(roles_of_user.toArray(new String[0]), ",");
  				file_store.setProperty(user, roles);
  			}
  			// Remove the role entry
  			role_list.remove(rolename);
  
  			// And commit the file_store to disk
  			try {
  				saveRoles();
  			} catch (IOException e) {
  				throw new RolesException(e);
  			}
  		} else {
  			throw new RolesException("Cannot find role '" + rolename + "'!");
  		}
  	}
docs: Delete a role.
  
  @param rolename
  The name of the role to delete.
  @throws RolesException
  if there was an error during deletion.