docs: function getAst(load, sourceMapFileName){
  	if(load.ast) {
  		return load.ast;
  	}
  
  	var fileName = sourceMapFileName || load.map && load.map.file;
  
  	load.ast = esprima.parse(load.source.toString(), {
  		loc: true,
  		source: fileName || load.address
  	});
  
  	if(load.map) {
  		sourceMapToAst(load.ast, load.map);
  	}
  
  	return load.ast;
  }