@Test(expectedExceptions = SystemException.class)
public void testDecompressShouldThrowExceptionWhenStreamCopyThrowsIOException() throws IOException {

    //GIVEN
    given(gzipInputStreamFactory.createInputStream(source)).willReturn(gzipInputStream);
    given(gzipInputStream.read((byte[]) Mockito.any())).willThrow(new IOException());
    //WHEN
    underTest.decompress(source);
    //THEN it should throw exception
}