final BeanDesc beanDesc = new BeanDescImpl(MyBean.class);
        assertThat(beanDesc.hasFieldDesc("HOGE"), is(true));
        final FieldDesc fieldDesc = beanDesc.getFieldDesc("HOGE");
        assertThat(fieldDesc.getFieldName(), is("HOGE"));
        assertThat(beanDesc.hasFieldDesc("aaa"), is(true));
        assertThat(beanDesc.hasFieldDesc("aaA"), is(not(true)));
    }

    /**
     * @throws Exception
     */

     *
     * @param fieldName
     *            The field name. Must not be {@literal null} or empty string
     * @return Whether the {@link FieldDesc} exists
     */
    boolean hasFieldDesc(String fieldName);

    /**
     * Returns the {@link FieldDesc}.
     *
     * @param fieldName
     *            The field name. Must not be {@literal null} or empty string
     * @return {@link FieldDesc}

    }

    @Override
    public Iterable<PropertyDesc> getPropertyDescs() {
        return unmodifiableCollection(propertyDescCache.values());
    }

    @Override
    public boolean hasFieldDesc(final String fieldName) {
        assertArgumentNotEmpty("fieldName", fieldName);

        return fieldDescCache.containsKey(fieldName);
    }

    @Override