}

    @Override
    public FieldDesc getFieldDesc(final String fieldName) {
        assertArgumentNotEmpty("fieldName", fieldName);

        final FieldDesc fieldDesc = fieldDescCache.get(fieldName);
        if (fieldDesc == null) {
            throw new FieldNotFoundRuntimeException(beanClass, fieldName);
        }
        return fieldDesc;
    }

    @Override

     * @return {@link FieldDesc}
     */
    FieldDesc getFieldDesc(String fieldName);

    /**
     * Returns the {@link FieldDesc}.
     *
     * @param index
     *            The index of the {@link FieldDesc}
     * @return {@link FieldDesc}
     */
    FieldDesc getFieldDesc(int index);

    /**
     * Returns the number of {@link FieldDesc}.
     *

        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)));
    }

    /**