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public String getDisplayName(boolean daylight,
                             int style,
                             Locale locale)

    Returns a name of this time zone suitable for presentation to the user in the specified locale. If the display name is not available for the locale, then this method returns a string in the normalized custom ID format.

    Parameters:
        daylight - if true, return the daylight savings name.
        style - either LONG or SHORT
        locale - the locale in which to supply the display name.
    Returns:
        the human-readable name of this time zone in the given locale.
    Throws:
        IllegalArgumentException - style is invalid.
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From this description it is not clear what will be returned if:

* true is passed as first argument to this method
* useDaylightTime() returns true for this TimeZone instance

As far as I see from 6300580 this method shall not take into account value of useDaylightTime() and return DST display name.

However this decision should be reflected in javadocs.