AssignUids tries to assign unique ids to each identity in the subjects and objects in the format of _:xxx.

convert the new UIDs to hex string.

ProcessGraph processes the SubGraph instance accumulating result for the query from different instances.

ToJson converts the list of subgraph into a JSON response by calling toFastJSON.

ToSubGraph converts the GraphQuery into the pb.SubGraph instance type.

DebugKey is the key used to toggle debug mode.

TODO: This looks unnecessary.

Function holds the information about gql functions.

Latency is used to keep track of the latency involved in parsing and processing the query.

QueryRequest wraps the state that is used when executing query.

SubGraph is the way to represent data pb.y.

ContextKey is used to set options in the context object.