docs: function get_node_style(node)
  {
  	return Object.keys(node)
  	// get all CSS styles of this style class node
  	.filter(property => typeof(node[property]) !== 'object')
  	// for each CSS style of this style class node
  	.reduce(function(style, style_property)
  	{
  		style[style_property] = node[style_property]
  		return style
  	}, 
  	{})
  }