@Test
  public void gc_memberWithCommas() {
    buffer = "gc --member=m1,m2";
    GfshParseResult result = parser.parse(buffer);
    assertThat(result.getParamValueAsString("member")).isEqualTo("m1,m2");
  }
This characterizes the current behavior but it may be incorrect.
geode-gfsh/src/integrationTest/java/org/apache/geode/management/internal/cli/OptionAliasesParsingTest.java