Bug 107590 [source action] 'Override method' content assist does not use parameter names from overridden method
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/OverrideCompletionProposal.java
private IJavaProject fJavaProject;
	private String fMethodName;
	private String[] fParamTypes;
	public OverrideCompletionProposal(IJavaProject jproject, ICompilationUnit cu, String methodName, String[] paramTypes, int start, int length, String displayName, String completionProposal) {
		super(completionProposal, cu, start, length, null, displayName, 0);
		Assert.isNotNull(jproject);
		Assert.isNotNull(methodName);
		Assert.isNotNull(paramTypes);
		Assert.isNotNull(cu);
		fParamTypes= paramTypes;
		fMethodName= methodName;
		fJavaProject= jproject;
		
		StringBuffer buffer= new StringBuffer();
		buffer.append(completionProposal);
		buffer.append(" {};"); 
		
		setReplacementString(buffer.toString());
	}
	/*
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension3#getPrefixCompletionText(org.eclipse.jface.text.IDocument,int)
	 */
	public CharSequence getPrefixCompletionText(IDocument document, int completionOffset) {
		return fMethodName;
	}
	/*
	 * @see JavaTypeCompletionProposal#updateReplacementString(IDocument,char,int,ImportsStructure)