Bug 115711 [content assist] Parameter hints disappear immediately
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/ParameterGuessingProposal.java
char[] signature= SignatureUtil.fix83600(fProposal.getSignature());
		char[][] types= Signature.getParameterTypes(signature);
		String[][] ret= new String[types.length][2];
		for (int i= 0; i < types.length; i++) {
			char[] type= SignatureUtil.getLowerBound(types[i]);
			ret[i][0]= String.valueOf(Signature.getSignatureQualifier(type));
			ret[i][1]= String.valueOf(Signature.getSignatureSimpleName(type));
		}
		return ret;
	}
	/*
	 * @see ICompletionProposal#getSelection(IDocument)
	 */
	public Point getSelection(IDocument document) {
		if (fSelectedRegion == null)
			return new Point(getReplacementOffset(), 0);
		return new Point(fSelectedRegion.getOffset(), fSelectedRegion.getLength());
	}
	private void openErrorDialog(Exception e) {
		Shell shell= getTextViewer().getTextWidget().getShell();
		MessageDialog.openError(shell, JavaTextMessages.ParameterGuessingProposal_error_msg, e.getMessage());
	}
	/*
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		return getDisplayString() + super.toString();
	}
	private void ensurePositionCategoryInstalled(final IDocument document, LinkedModeModel model) {
		if (!document.containsPositionCategory(getCategory())) {