presto-memory-context/src/main/java/io/prestosql/memory/context/MemoryTrackingContext.java/MemoryTrackingContext/localRevocableMemoryContext
class MemoryTrackingContext:    public LocalMemoryContext localRevocableMemoryContext()
    {
        verifyNotNull(revocableLocalMemoryContext, "local memory contexts are not initialized");
        return revocableLocalMemoryContext;
    }