Check if the response contains records

Purpose/Overview:
During the harvesting mod-oai-pmh sends instance uuid to srs to retrieve the underlying record. If the instance does not have underlying SRS record, nothing is included in the output. In some cases when max record per response is small, it might happen that the response will contain resumption token only and no records.

Requirements/Scope:

1. Check if the response from mod-oai-pmh contains records and not only resumptionToken
2. If there are no records, the module will re-send request to mod-oai-pmh using provided resumptionToken.

Approach:

Acceptance criteria:

• edge-oai-pmh does not return responses with no harvested records and resumption token only