Error with Jakarta-commons HashCodeBuilder

I found interesting error in the code, which was very difficult to find out:

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return new HashCodeBuilder()
        .append(param1)
        .append(param2)
        .hashCode();
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This code is working incorrectly - it calculates different hash-code every time. This happening, because method ".hashCode()" is called on instance of class "HashCodeBuilder".

Instead of ".hashCode()" is needed to use ".toHashCode()".