OSID - osid.metering.MeterUtilityAssignmentSession Service Interface Definition

Interface	osid.metering.MeterUtilityAssignmentSession
Implements	`osid.OsidSession`
Description	This session provides methods to re-assign `Meters` to `Utility` objects A `Meter` may appear in multiple `Utility` objects and removing the last reference to a `Meter` is the equivalent of deleting it. Each `Utility` may have its own authorizations governing who is allowed to operate on it. Moving or adding a reference of a `Meter` to another `Utility` is not a copy operation (eg: does not change its `Id` ).
Method	canAssignMeters
Description	Tests if this user can alter meter/utility mappings. A return of true does not guarantee successful authorization. A return of false indicates that it is known mapping methods in this session will result in a `PERMISSION_DENIED.` This is intended as a hint to an application that may opt not to offer assignment operations to unauthorized users.
Return	`boolean`		`false` if mapping is not authorized, `true` otherwise
Compliance	`mandatory`		This method must be implemented.
Method	canAssignMetersToUtility
Description	Tests if this user can alter meter/utility mappings. A return of true does not guarantee successful authorization. A return of false indicates that it is known mapping methods in this session will result in a `PERMISSION_DENIED` . This is intended as a hint to an application that may opt not to offer assignment operations to unauthorized users.
Parameters	`osid.id.Id`	`utilityId`	the `Id` of the `Utility`
Return	`boolean`		`false` if mapping is not authorized, `true` otherwise
Errors	NULL_ARGUMENT		`utilityId` is `null`
Compliance	`mandatory`		This method must be implemented.
Method	getAssignableUtilityIds
Description	Gets a list of utilities including and under the given utility node in which any meter can be assigned.
Parameters	`osid.id.Id`	`utilityId`	the `Id` of the `Utility`
Return	`osid.id.IdList`		list of assignable utility `Ids`
Errors	NULL_ARGUMENT		`utilityId` is `null`
Errors	OPERATION_FAILED		unable to complete request
Compliance	`mandatory`		This method must be implemented.
Method	getAssignableUtilityIdsForMeter
Description	Gets a list of utilities including and under the given utility node in which a specific meter can be assigned.
Parameters	`osid.id.Id`	`utilityId`	the `Id` of the `Utility`
Parameters	`osid.id.Id`	`meterId`	the `Id` of the `Meter`
Return	`osid.id.IdList`		list of assignable utility `Ids`
Errors	NULL_ARGUMENT		`utility` or `meterId` is `null`
Errors	OPERATION_FAILED		unable to complete request
Compliance	`mandatory`		This method must be implemented.
Method	assignMeterToUtility
Description	Adds an existing `Meter` to a `Utility.`
Parameters	`osid.id.Id`	`meterId`	the `Id` of the `Meter`
Parameters	`osid.id.Id`	`utilityId`	the `Id` of the `Utility`
Errors	ALREADY_EXISTS		`meterId` is already assigned to `utilityId`
	NOT_FOUND		`meterId` or `utilityId` not found
	NULL_ARGUMENT		`meterId` or `utilityId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.
Method	unassignMeterFromUtility
Description	Removes a `Meter` from a `Utility.`
Parameters	`osid.id.Id`	`meterId`	the `Id` of the `Meter`
Parameters	`osid.id.Id`	`utilityId`	the `Id` of the `Utility`
Errors	NOT_FOUND		`meterId` or `utilityId` not found or `meterId` not assigned to `utilityId`
	NULL_ARGUMENT		`meterId` or `utilityId` is `null`
	OPERATION_FAILED		unable to complete request
	PERMISSION_DENIED		authorization failure
Compliance	`mandatory`		This method must be implemented.