Bug 4139 EC DCR: Code templates feature (1GIVMDV)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/template/TemplateInterpolator.java
switch (ch) {
				case IDENTIFIER_END:
					{
						String value= evaluator.evaluate(identifier.toString(), buffer.length());
					
						if (value == null) {
							
							buffer.append(ESCAPE_CHARACTER);
							buffer.append(IDENTIFIER_BEGIN);
							buffer.append(identifier);
							buffer.append(IDENTIFIER_END);
						} else {							
							buffer.append(value);
						}
					}
					state= TEXT;
					break;
				
				default:
					identifier.append(ch);
					break;
				}
				break;
			}			
		}
		
		return buffer.toString();
	}
}