private TensorModifyUpdate.Operation decodeOperation(byte operationId) {
        byte OP_MASK = 0b01111111;
        return TensorModifyUpdate.Operation.getOperation(operationId & OP_MASK);
    }
Class used for de-serializing documents on the current head document format.

@author baldersheim
document/src/main/java/com/yahoo/document/serialization/VespaDocumentDeserializerHead.java