java - How to stub method returning Long in Spock? -

i have been trying stub method returning long null. there way this?

interface clock {     long currenttimemillis(); }  def "stub method returning long"() {     clock clock = mock(clock)     clock.currenttimemillis() >> 1      when:     long currenttime = clock.currenttimemillis()      then:     currenttime == 1     1 * clock.currenttimemillis() }  def "mock method returning longs"() {     clock clock = mock(clock)     clock.currenttimemillis() >>> [1, 2, 3]      when:     long currenttime = clock.currenttimemillis()      then:     currenttime == 1     1 * clock.currenttimemillis() } 

in both tests i'm getting following error:

condition not satisfied:    currenttime == 1   |           |   null        false 

when both mock , record behavior, should defined below.

here's how works:

@grab('org.spockframework:spock-core:0.7-groovy-2.0') @grab('cglib:cglib-nodep:3.1')  import spock.lang.*   class test extends specification {     def "stub method returning long"() {         given:         clock clock = mock(clock)          when:         long currenttime = clock.currenttimemillis()          then:         currenttime == 1         1 * clock.currenttimemillis() >> 1     }      def "mock method returning longs"() {         given:         clock clock = mock(clock)          when:         long currenttime = clock.currenttimemillis()          then:         currenttime == 1         1 * clock.currenttimemillis() >>> [1, 2, 3]     } }  interface clock {     long currenttimemillis(); }