code: private int findStartVariable(final String aKey) {
  		if (aKey == null) {
  			return -1;
  		}
  
  		// Look for the first occurence of ${ in the parameter.
  		int index = aKey.indexOf('$');
  
  		for (; index >= 0; index = aKey.indexOf('$', index + 1)) {
  			if (index == aKey.length() - 1) {
  				continue;
  			}
  
  			if (aKey.charAt(index + 1) != '{') {
  				continue;
  			}
  
  			// Ahh - got it
  			break; // NOPMD
  		}
  
  		return index;
  	}
docs: Finds the start of a variable name in the given string. Variables use the "${<i>variableName</i>}" notation.
  
  @param aKey the key to search.
  @return the index of the start of a variable name in the given string, or -1 if not found.