add common function to Unit layer

com/Unit/_common.lua

@@ -0,0 +1,23 @@
+-- File com/Unit/_common.lua
+--
+-- Created at 2025-05-10 18:23
+--
+-- Updated at - 
+-- Description:
+--- Common functions for Unit module
+
+local common = {}
+
+function common.CheckMissingElement(arr, cmp)
+  local is_missing = {}
+  local ok = true
+  for _, key in ipairs(arr) do
+    if cmp[key] == nil then
+      table.insert(is_missing, key)
+      ok = false
+    end
+  end
+  return ok, is_missing
+end
+
+return common