brn: Introduce BRN as a class

app/brm/utils.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+from typing import Any
+
+
+def is_integer(n: Any) -> bool:
+    """
+    Determine if a string (or other object type that can be converted automatically) represents an integer.
+
+    Thanks to https://note.nkmk.me/en/python-check-int-float/.
+
+    :param n: object to test
+    :return: true if it's an integer
+    """
+    try:
+        float(n)
+    except ValueError:
+        return False
+    else:
+        return float(n).is_integer()