function applyDefaults(object, sourceOptions){
  sourceOptions = sourceOptions || {};

  // create a copy rather than mutating
  var options = {};
  options.algorithm = sourceOptions.algorithm || 'sha1';
  options.encoding = sourceOptions.encoding || 'hex';
  options.excludeValues = sourceOptions.excludeValues ? true : false;
  options.algorithm = options.algorithm.toLowerCase();
  options.encoding = options.encoding.toLowerCase();
  options.ignoreUnknown = sourceOptions.ignoreUnknown !== true ? false : true; // default to false
  options.respectType = sourceOptions.respectType === false ? false : true; // default to true
  options.respectFunctionNames = sourceOptions.respectFunctionNames === false ? false : true;
  options.respectFunctionProperties = sourceOptions.respectFunctionProperties === false ? false : true;
  options.unorderedArrays = sourceOptions.unorderedArrays !== true ? false : true; // default to false
  options.unorderedSets = sourceOptions.unorderedSets === false ? false : true; // default to false
  options.unorderedObjects = sourceOptions.unorderedObjects === false ? false : true; // default to true
  options.replacer = sourceOptions.replacer || undefined;
  options.excludeKeys = sourceOptions.excludeKeys || undefined;

  if(typeof object === 'undefined') {
    throw new Error('Object argument required.');
  }

  // if there is a case-insensitive match in the hashes list, accept it
  // (i.e. SHA256 for sha256)
  for (var i = 0; i < hashes.length; ++i) {
    if (hashes[i].toLowerCase() === options.algorithm.toLowerCase()) {
      options.algorithm = hashes[i];
    }
  }

  if(hashes.indexOf(options.algorithm) === -1){
    throw new Error('Algorithm "' + options.algorithm + '"  not supported. ' +
      'supported values: ' + hashes.join(', '));
  }

  if(encodings.indexOf(options.encoding) === -1 &&
     options.algorithm !== 'passthrough'){
    throw new Error('Encoding "' + options.encoding + '"  not supported. ' +
      'supported values: ' + encodings.join(', '));
  }

  return options;
}
Exported sugar methods

@param {object} object value to hash
@return {string} hash value
@api public