text: 'use strict';
  
  exports.type = 'full';
  
  exports.active = true;
  
  exports.description = 'removes unused namespaces declaration';
  
  /**
   * Remove unused namespaces declaration.
   *
   * @param {Object} item current iteration item
   * @return {Boolean} if false, item will be filtered out
   *
   * @author Kir Belevich
   */
  exports.fn = function(data) {
  
      var svgElem,
          xmlnsCollection = [];
  
      /**
       * Remove namespace from collection.
       *
       * @param {String} ns namescape name
       */
      function removeNSfromCollection(ns) {
  
          var pos = xmlnsCollection.indexOf(ns);
  
          // if found - remove ns from the namespaces collection
          if (pos > -1) {
              xmlnsCollection.splice(pos, 1);
          }
  
      }
  
      /**
       * Bananas!
       *
       * @param {Array} items input items
       *
       * @return {Array} output items
       */
      function monkeys(items) {
  
          var i = 0,
              length = items.content.length;
  
          while(i < length) {
  
              var item = items.content[i];
  
              if (item.isElem('svg')) {
  
                  item.eachAttr(function(attr) {
                      // collect namespaces
                      if (attr.prefix === 'xmlns' && attr.local) {
                          xmlnsCollection.push(attr.local);
                      }
                  });
  
                  // if svg element has ns-attr
                  if (xmlnsCollection.length) {
                      // save svg element
                      svgElem = item;
                  }
  
              } else if (xmlnsCollection.length) {
  
                  // check item for the ns-attrs
                  if (item.prefix) {
                      removeNSfromCollection(item.prefix);
                  }
  
                  // check each attr for the ns-attrs
                  item.eachAttr(function(attr) {
                      removeNSfromCollection(attr.prefix);
                  });
  
              }
  
              // if nothing is found - go deeper
              if (xmlnsCollection.length && item.content) {
                  monkeys(item);
              }
  
              i++;
  
          }
  
          return items;
  
      }
  
      data = monkeys(data);
  
      // remove svg element ns-attributes if they are not used even once
      if (xmlnsCollection.length) {
          xmlnsCollection.forEach(function(name) {
              svgElem.removeAttr('xmlns:' + name);
          });
      }
  
      return data;
  
  };
  