def request(query, params):
params['<STR_LIT:url>'] = '<STR_LIT>' % query<EOL>return params<EOL>
pre-request callback
    params<dict>:
      method  : POST/GET
      headers : {}
      data    : {} # if method == POST
      url     : ''
      category: 'search category'
      pageno  : 1 # number of the requested page