@Test
  public void isTypeConvertibleShouldReturnTrueForCharacterPrimitivesAndWrappers() {
    assertThat(TypeUtils.isTypeConvertible(null, Character.class)).isTrue();
    assertThat(TypeUtils.isTypeConvertible(Character.TYPE, Character.TYPE)).isTrue();
    assertThat(TypeUtils.isTypeConvertible(Character.TYPE, Character.class)).isTrue();
    assertThat(TypeUtils.isTypeConvertible(Character.class, Character.TYPE)).isTrue();
    assertThat(TypeUtils.isTypeConvertible(Character.class, Character.class)).isTrue();
  }
Can't test every possible combination so try the known, relevant ones.
geode-core/src/test/java/org/apache/geode/cache/query/internal/types/TypeUtilsJUnitTest.java