Executing the following command

emulator.exe -engine classic -ports 5800,5801 -report-console tcp:5863,max=60 -avd Nexus_S_API_23 -no-snapshot-load -no-snapshot-save -engine auto -noaudio -gpu off

FAILURE: Build failed with an exception.
18:04:52
18:04:52 * What went wrong:
18:04:52 Execution failed for task ':app:connectedDebugAndroidTest'.
18:04:52 > com.android.builder.testing.api.DeviceException: No connected devices!
18:04:52

When I run the command  on command prompt, I get the following

emulator: trying to find console-report client on tcp:5554
emulator: trying to find console-report client on tcp:5554
emulator: trying to find console-report client on tcp:5554
emulator: trying to find console-report client on tcp:5554
emulator: trying to find console-report client on tcp:5554
emulator: ERROR: could not connect to server on TCP:5554: connection refused
emulator: Done with QEMU main loop
emulator: User-config was not changed.