code: def filter_columns(
      self, result: pd.DataFrame, query: ast.Select = None
  ):
      columns = []
      if query is not None:
          for target in query.targets:
              if isinstance(target, ast.Star):
                  columns = self.get_columns()
                  break
              elif isinstance(target, ast.Identifier):
                  columns.append(target.parts[-1])
              else:
                  raise NotImplementedError
      else:
          columns = self.get_columns()
  
      columns = [name.lower() for name in columns]
  
      if len(result) == 0:
          result = pd.DataFrame([], columns=columns)
      else:
          for col in set(columns) & set(result.columns) ^ set(columns):
              result[col] = None
  
          result = result[columns]
  
      if query is not None and query.limit is not None:
          return result.head(query.limit.value)
  
      return result
  
file_path: mindsdb/mindsdb/integrations/handlers/reddit_handler/reddit_tables.py
imports: import pandas
  from mindsdb.integrations.libs.api_handler import APITable
  from mindsdb_sql.parser import ast
  from mindsdb.integrations.utilities.sql_utils import extract_comparison_conditions
label_desc: Use image node_id 3 for calling the SubmissionTable obj's underlying member method code with example usage: obj.filter_columns(result, query) and returns: result, result