Bug 43488 [typing] BadPositionCategoryException in LinkedPositionManager
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/link/contentassist/ContentAssistant2.java
public void setCompletions(String[] proposals) {
		fProposalStrings= proposals;
	}
	/**
	 * @param proposals
	 */
	public void setCompletions(ICompletionProposal[] proposals) {
		fProposals= proposals;
		setProposalChosen(false);
	}
	
	/*
	 * @see org.eclipse.jface.text.IWidgetTokenKeeperExtension#requestWidgetToken(org.eclipse.jface.text.IWidgetTokenOwner, int)
	 * @since 3.0
	 */
	public boolean requestWidgetToken(IWidgetTokenOwner owner, int priority) {
		if (priority > WIDGET_PRIORITY) {
			hidePossibleCompletions();
			return true;
		} else
			return false;
	}
	/*
	 * @see org.eclipse.jface.text.IWidgetTokenKeeperExtension#setFocus(org.eclipse.jface.text.IWidgetTokenOwner)
	 * @since 3.0
	 */
	public void setFocus(IWidgetTokenOwner owner) {
		if (fProposalPopup != null)
			fProposalPopup.setFocus();
	}