}
private void validateFunctionJoin(DataStructure input, Operation previousOp) {
assert (input != null) : "This method should not be called with a null input structure";
OperationFunctionInfo info = new OperationFunctionInfo(previousOp);
Function last = info.getLastNonPassThroughFunction();
if (last != null) {
DataStructure output = last.getOutputStructure();
if (output != null && input.isCompatibleWith(output)) {
return;
}
}
fatal("The source structure of this operation is not compatible with the target structure of the "