docs: def _create_solr_query(self, line):
          """Actual search - easier to test. """
          p0 = ""
          if line:
              p0 = line.strip()
          p1 = self._query_string_to_solr_filter(line)
          p2 = self._object_format_to_solr_filter(line)
          p3 = self._time_span_to_solr_filter()
          result = p0 + p1 + p2 + p3
          return result.strip()