@Test
public void testDecompressShouldDoDecompression() throws IOException {

    //GIVEN
    given(gzipInputStreamFactory.createInputStream(source)).willReturn(gzipInputStream);
    given(gzipInputStream.read((byte[]) Mockito.any())).willReturn(1, -1);
    //WHEN
    underTest.decompress(source);
    //THEN
    verify(gzipInputStream, times(2)).read(Mockito.any(byte[].class));
}