private boolean removeInternal(DataType dataType) {
		if (!contains(dataType)) {
			return false;
		}

		long id = getID(dataType);
		if (id <= 0) { // removal of certain special types not permitted
			return false;
		}

		idsToDelete.add(id);
		removeQueuedDataTypes();
		return true;
	}
Remove the given datatype from this manager (assumes the lock has already been acquired).

@param dataType the dataType to be removed
@return true if datatype removal was successful, else false
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java