public ObjectTypeAssert isMapOf(Class keyType, Class valueType) {
    isNotNull();
    isExactlyInstanceOf(MapTypeImpl.class);
    org.assertj.core.api.Assertions.assertThat(((MapTypeImpl) actual).getKeyType())
        .isExactlyInstanceOf(keyType);
    org.assertj.core.api.Assertions.assertThat(((MapTypeImpl) actual).getElementType())
        .isExactlyInstanceOf(valueType);

    return this;
  }
Custom Assertion to validate {@link ObjectType} instances.
geode-core/src/test/java/org/apache/geode/cache/query/internal/types/ObjectTypeAssert.java