chore: import upstream snapshot with attribution

fun_text_processing/text_normalization/en/verbalizers/abbreviation.py

@@ -0,0 +1,21 @@
+import pynini
+from fun_text_processing.text_normalization.en.graph_utils import DAMO_NOT_QUOTE, GraphFst
+from pynini.lib import pynutil
+
+
+class AbbreviationFst(GraphFst):
+    """
+    Finite state transducer for verbalizing abbreviations
+        e.g. tokens { abbreviation { value: "A B C" } } -> "ABC"
+
+    Args:
+        deterministic: if True will provide a single transduction option,
+            for False multiple transduction are generated (used for audio-based normalization)
+    """
+
+    def __init__(self, deterministic: bool = True):
+        super().__init__(name="abbreviation", kind="verbalize", deterministic=deterministic)
+
+        graph = pynutil.delete('value: "') + pynini.closure(DAMO_NOT_QUOTE, 1) + pynutil.delete('"')
+        delete_tokens = self.delete_tokens(graph)
+        self.fst = delete_tokens.optimize()