def fetch_compare(older, newer)
      unless @compares["#{older}...#{newer}"]
        compare_data = check_github_response { @client.compare(user_project, older, newer || "HEAD") }
        raise StandardError, "Sha #{older} and sha #{newer} are not related; please file a github-changelog-generator issues and describe how to replicate this issue." if compare_data["status"] == "diverged"

        @compares["#{older}...#{newer}"] = stringify_keys_deep(compare_data.to_hash)
      end
      @compares["#{older}...#{newer}"]
    end
def fetch_compare(older, newer)
      unless @compares["#{older}...#{newer}"]
        compare_data = check_github_response { @client.compare(user_project, older, newer || "HEAD") }
        raise StandardError, "Sha #{older} and sha #{newer} are not related; please file a github-changelog-generator issues and describe how to replicate this issue." if compare_data["status"] == "diverged"

        @compares["#{older}...#{newer}"] = stringify_keys_deep(compare_data.to_hash)
      end
      @compares["#{older}...#{newer}"]
    end
Fetch and cache comparison between two github refs

 @param [String] older The older sha/tag/branch.
 @param [String] newer The newer sha/tag/branch.
 @return [Hash] Github api response for comparison.