old_contents: 'use strict';
  
  var createElement = require( './../lib' );
  
  var opts = {
  	'className': 'eqn',
  	'align': 'left',
  	'raw': '\\operatorname{erf}(x) = \\frac{2}{\\sqrt\\pi}\\int_0^x e^{-t^2}\\,\\mathrm dt',
  	'label': 'eq:erf',
  	'src': 'https://cdn.rawgit.com/stdlib-js/stdlib/master/lib/node_modules/@stdlib/math/base/special/erf/docs/img/eqn.svg',
  	'alt': 'Error function.'
  };
  
  var html = createElement( opts );
  
  console.log( html );
  /* =>
      '<div class="eqn" align="left" data-raw-text="\operatorname{erf}(x) = \frac{2}{\sqrt\pi}\int_0^x e^{-t^2}\,\mathrm dt" data-equation="eq:erf">
        <img src="https://cdn.rawgit.com/stdlib-js/stdlib/master/lib/node_modules/@stdlib/math/base/special/erf/docs/img/eqn.svg" alt="Error function.">
        <br>
      </div>'
  */
  
new_contents: 'use strict';
  
  var createElement = require( './../lib' );
  
  var opts = {
  	'className': 'eqn',
  	'align': 'left',
  	'raw': '\\operatorname{erf}(x) = \\frac{2}{\\sqrt\\pi}\\int_0^x e^{-t^2}\\,\\mathrm dt',
  	'label': 'eq:erf',
  	'src': 'https://cdn.rawgit.com/stdlib-js/stdlib/master/lib/node_modules/@stdlib/math/base/special/erf/docs/img/eqn.svg',
  	'alt': 'Error function.'
  };
  
  var html = createElement( opts );
  
  console.log( html );
  // => '<div class="eqn" align="left" data-raw-text="\operatorname{erf}(x) = \frac{2}{\sqrt\pi}\int_0^x e^{-t^2}\,\mathrm dt" data-equation="eq:erf">\n    <img src="https://cdn.rawgit.com/stdlib-js/stdlib/master/lib/node_modules/@stdlib/math/base/special/erf/docs/img/eqn.svg" alt="Error function.">\n    <br>\n</div>'
  
subject: Update return value