WS error handling based on poor input values

WS input to identify an object when a null/empty "UUID"="" value and "NAME"="a value" supplied.

returns no results
instead of:

• ignoring empty UUID value
•    or
• identifying that no search could be done due to missing/bad Lookup values.

This likely could be extended to error handling additions for conditions like:
What to do when UUID="a value" and NAME="an Other value" and no matching object is found.

Example input WS calls:
POST /grouper-ws/servicesRest/v2_2_000/attributeAssignments
{
...
"WsRestGetAttributeAssignmentsRequest":{
"attributeAssignType":"group",
"includeAssignmentsOnAssignments":"T",
"wsOwnerGroupLookups":[
{
"name":"bla:bla:foo:bar",
"uuid":""
}
]
}
...
}

POST /grouper-ws/servicesRest/v2_2_000/attributeAssignments
{
...
"WsRestGetAttributeAssignmentsRequest":{
"attributeAssignType":"group",
"includeAssignmentsOnAssignments":"T",
"wsOwnerGroupLookups":[
{
"name":"",
"uuid":"bla-bla-bla"
}
]
}
...
}

POST /grouper-ws/servicesRest/v2_2_000/attributeAssignments
{
...
"WsRestGetAttributeAssignmentsRequest":{
"attributeAssignType":"group",
"includeAssignmentsOnAssignments":"T",
"wsOwnerGroupLookups":[
{
"name":"bla:bla:foo:bar",
"uuid":"bla-bla-bla"
}
]
}
...
}