docstr: The get_keywords method receives the data-a specific document returned by the API, gets the specified keywords 
  and combines them in a string, so as to allow the use of DataFrame.
  Args:
      data (CatalogDocument) : document returned by the API
  Returns:
      keywords string
docstr_tok: ["The","get_keywords","method","receives","the","data-a","specific","document","returned","by","the","API",",","gets","the","specified","keywords","and","combines","them","in","a","string",",","so","as","to","allow","the","use","of","DataFrame",".","Args",":","data","(","CatalogDocument",")",":","document","returned","by","the","API","Returns",":","keywords","string"]
code: def get_keywords(self, data):
      """The get_keywords method receives the data-a specific document returned by the API, gets the specified keywords
      and combines them in a string, so as to allow the use of DataFrame.
      Args:
          data (CatalogDocument) : document returned by the API
      Returns:
          keywords string
      """
      keywords = ""
      sum = 0
      if data.keywords != None:
          for x in data.keywords:
              if sum + 1 == len(data.keywords):
                  keywords = keywords + x + " "
              else:
                  if x != None:
                      keywords = keywords + x + ", "
                      sum = sum + 1
      return keywords
  
file_path: mindsdb/mindsdb/integrations/handlers/mendeley_handler/mendeley_handler.py
imports: from mindsdb_sql import parse_sql
  import pandas
  from mendeley import Mendeley
  from mindsdb.integrations.libs.api_handler import APIHandler, FuncParser
  from mendeley.session import MendeleySession
  from mindsdb.integrations.handlers.mendeley_handler.mendeley_tables import CatalogSearchTable
  from mindsdb.utilities import log
  from typing import Dict
  from mindsdb.integrations.libs.response import HandlerStatusResponse, HandlerResponse, RESPONSE_TYPE
label_desc: Use image node_id 6 for calling the MendeleyHandler obj's underlying member method code with example usage: obj.get_keywords(data) and returns: keywords