code: protected int checkResponse(TCPReadRequestContext rsc) {
          // Parse the proxy server response
          //
          WsByteBuffer[] buffers = rsc.getBuffers();
  
          // check if the correct response was received
          if (null == buffers) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "Could not complete proxy handshake, null buffers");
              }
              return STATUS_ERROR;
          }
          int status = validateProxyResponse(buffers);
          if (STATUS_DONE == status) {
              releaseProxyReadBuffer();
          }
          return status;
      }
docs: Check for a proxy handshake response.
  
  @param rsc
  @return int (status code)