Add forgotten columncomparator file

util/columncomparator.py

@@ -0,0 +1,11 @@
+from typing import List
+
+from semanticlabeling.labeledcolumn import LabeledColumn
+
+
+class UncomparableException(Exception):
+    """Thrown when two labeled columns of uncomparable type are being compared"""
+
+
+def get_closest(compare_column: LabeledColumn, other_columns: List[LabeledColumn]) -> LabeledColumn:
+    raise NotImplementedError()