code: @Nullable
      public SchemaAndTable getOverride(SchemaAndTable key) {
          SchemaAndTable result = nameMapping.getOverride(key).or(key);
          if (schemaMapping.containsKey(key.getSchema())) {
              result = new SchemaAndTable(schemaMapping.get(key.getSchema()), result.getTable());
          }
          return result;
      }
docs: Get the schema/table override
  
  @param key schema and table
  @return overridden schema and table