function hasValidExclusion(exclusion, textAfterCursor) {
        return (exclusion && exclusion === textAfterCursor);
    }
Test whether the provider has an exclusion that is still the same as text after the cursor.

@param {string} exclusion - Text not to be overwritten when the provider inserts the selected hint.
@param {string} textAfterCursor - Text that is immediately after the cursor position.
@return {boolean} true if the exclusion is not null and is exactly the same as textAfterCursor,
false otherwise.