code: def fetch_protein_list(self, taxon_id):
          
          protein_list = list()
          # col = self.columns['ensembl_biomart']
          col = ['ensembl_peptide_id', ]
  
          params = urllib.parse.urlencode(
              {'query': self._build_biomart_gene_query(taxon_id, col)})
          conn = http.client.HTTPConnection(ENS_URL)
          conn.request("GET", '/biomart/martservice?' + params)
          response = conn.getresponse()
  
          for line in response:
              line = line.decode('utf-8').rstrip()
              row = line.split('\t')
              if len(row) != len(col):
                  LOG.warning("Data error for p-list query on %d", taxon_id)
                  continue
              protein_list.append(row[col.index('ensembl_peptide_id')])
          conn.close()
          return protein_list
docs: Fetch a list of proteins for a species in biomart
          :param taxid:
          :return: list