code: @Override
  	public TextTemplate interpolate(final Map<String, ?> variables)
  	{
  		if (variables != null)
  		{
  			final String result = new MapVariableInterpolator(buffer.toString(), variables)
  				.toString();
  			buffer.delete(0, buffer.length());
  			buffer.append(result);
  		}
  		return this;
  	}
docs: {@inheritDoc}