code: protected void convertPrimitiveToWrapper(
  			final LightweightTypeReference primitive, 
  			final LightweightTypeReference wrapper, 
  			final ITreeAppendable appendable,
  			final Later expression) {
  		appendable.append(wrapper);
  		appendable.append(".");
  		appendable.append("valueOf(");
  		expression.exec(appendable);
  		appendable.append(")");
  	}
docs: Convert a primitive expression (number, char, boolean) to its wrapper equivalent.
  
  @param primitive unused in this context but useful for inheritors.
  @param wrapper the wrapper type to convert to.
  @param appendable the receiver of the convertion.
  @param expression the expression to convert.