add

ccxt/static_dependencies/ethereum/utils/encoding.py

@@ -0,0 +1,6 @@
+def int_to_big_endian(value: int) -> bytes:
+    return value.to_bytes((value.bit_length() + 7) // 8 or 1, "big")
+
+
+def big_endian_to_int(value: bytes) -> int:
+    return int.from_bytes(value, "big")