How to use the sdp.isRejected function in sdp

sections.forEach(function(mediaSection, sdpMLineIndex) {
      var lines = SDPUtils.splitLines(mediaSection);
      var kind = SDPUtils.getKind(mediaSection);
      var rejected = SDPUtils.isRejected(mediaSection);
      var protocol = lines[0].substr(2).split(' ')[2];

      var direction = SDPUtils.getDirection(mediaSection, sessionpart);
      var remoteMsid = SDPUtils.parseMsid(mediaSection);

      var mid = SDPUtils.getMid(mediaSection) || SDPUtils.generateIdentifier();

      // Reject datachannels which are not implemented yet.
      if (kind === 'application' && protocol === 'DTLS/SCTP') {
        self.transceivers[sdpMLineIndex] = {
          mid: mid,
          isDatachannel: true
        };
        return;
      }

groups: [],
        media: []
    };

    for (const groupLine of SDP.matchPrefix(sessionPart, 'a=group:')) {
        const parts = groupLine.split(' ');
        const semantics = parts.shift()!.substr(8);
        session.groups.push({
            mids: parts,
            semantics
        });
    }

    for (const mediaSection of mediaSections) {
        const kind = SDP.getKind(mediaSection);
        const isRejected = SDP.isRejected(mediaSection);
        const mLine = SDP.parseMLine(mediaSection);

        const media: IntermediateMediaDescription = {
            direction: SDP.getDirection(mediaSection, sessionPart),
            kind,
            mid: SDP.getMid(mediaSection),
            protocol: mLine.protocol
            // TODO: what about end-of-candidates?
        };

        if (!isRejected) {
            media.iceParameters = SDP.getIceParameters(mediaSection, sessionPart);
            media.dtlsParameters = SDP.getDtlsParameters(mediaSection, sessionPart);
            media.setup = SDP.matchPrefix(mediaSection, 'a=setup:')[0].substr(8);
        }

sections.forEach(function(mediaSection, sdpMLineIndex) {
        var transceiver = self.transceivers[sdpMLineIndex];
        var iceGatherer = transceiver.iceGatherer;
        var iceTransport = transceiver.iceTransport;
        var dtlsTransport = transceiver.dtlsTransport;
        var localCapabilities = transceiver.localCapabilities;
        var remoteCapabilities = transceiver.remoteCapabilities;

        var rejected = SDPUtils.isRejected(mediaSection);

        if (!rejected && !transceiver.isDatachannel) {
          var remoteIceParameters = SDPUtils.getIceParameters(
              mediaSection, sessionpart);
          var remoteDtlsParameters = SDPUtils.getDtlsParameters(
              mediaSection, sessionpart);
          if (isIceLite) {
            remoteDtlsParameters.role = 'server';
          }

          if (!self.usingBundle || sdpMLineIndex === 0) {
            iceTransport.start(iceGatherer, remoteIceParameters,
                isIceLite ? 'controlling' : 'controlled');
            dtlsTransport.start(remoteDtlsParameters);
          }

sections.forEach(function(mediaSection, sdpMLineIndex) {
        var transceiver = self.transceivers[sdpMLineIndex];
        var iceGatherer = transceiver.iceGatherer;
        var iceTransport = transceiver.iceTransport;
        var dtlsTransport = transceiver.dtlsTransport;
        var localCapabilities = transceiver.localCapabilities;
        var remoteCapabilities = transceiver.remoteCapabilities;

        var rejected = SDPUtils.isRejected(mediaSection);

        if (!rejected && !transceiver.isDatachannel) {
          var remoteIceParameters = SDPUtils.getIceParameters(
              mediaSection, sessionpart);
          var remoteDtlsParameters = SDPUtils.getDtlsParameters(
              mediaSection, sessionpart);
          if (isIceLite) {
            remoteDtlsParameters.role = 'server';
          }

          if (!self.usingBundle || sdpMLineIndex === 0) {
            iceTransport.start(iceGatherer, remoteIceParameters,
                isIceLite ? 'controlling' : 'controlled');
            dtlsTransport.start(remoteDtlsParameters);
          }

sections.forEach(function(mediaSection, sdpMLineIndex) {
        var transceiver = self.transceivers[sdpMLineIndex];
        var iceGatherer = transceiver.iceGatherer;
        var iceTransport = transceiver.iceTransport;
        var dtlsTransport = transceiver.dtlsTransport;
        var localCapabilities = transceiver.localCapabilities;
        var remoteCapabilities = transceiver.remoteCapabilities;

        var rejected = SDPUtils.isRejected(mediaSection);

        if (!rejected && !transceiver.isDatachannel) {
          var remoteIceParameters = SDPUtils.getIceParameters(
              mediaSection, sessionpart);
          var remoteDtlsParameters = SDPUtils.getDtlsParameters(
              mediaSection, sessionpart);
          if (isIceLite) {
            remoteDtlsParameters.role = 'server';
          }

          if (!self.usingBundle || sdpMLineIndex === 0) {
            iceTransport.start(iceGatherer, remoteIceParameters,
                isIceLite ? 'controlling' : 'controlled');
            dtlsTransport.start(remoteDtlsParameters);
          }