I'm working on a program that uses REXML to parse SVG. One of the test
programs declares this entity:

<!ENTITY shape "        <path d='M60,0 l60,0 l60,60 l0,60 l-60,60 l-60,0
l-60,-60 l0,-60 z'/>">
]>

Then later it refers to the entity like this:

<g fill="yellow" stroke="red" stroke-width="8" >&shape;</g>

How do I get REXML to replace &shape; with its value and then parse it?