code: function _each (nodes, func, param, resultSet) {
          var
              idx,
              node;
          for (idx = 0; idx < nodes.length; ++idx) {
              node = nodes[idx];
              func(node, param, resultSet);
          }
      }
docs: /*
  var
  a/b/c
  _sample1 = {
  type: gpf.xml.NODE_ELEMENT,
  name: "a",
  then: {
  type: gpf.xml.NODE_ELEMENT,
  name: "b",
  then: {
  type: gpf.xml.NODE_ELEMENT,
  name: "c"
  }
  }
  },
  
  a[b and c]
  _sample2 = {
  type: gpf.xml.NODE_ELEMENT,
  name: "a",
  filter: {
  and: [ {
  type: gpf.xml.NODE_ELEMENT,
  name: "b"
  }, {
  type: gpf.xml.NODE_ELEMENT,
  name: "c"
  }]
  }
  },
  a[@d='1']
  _sample3 = {
  type: gpf.xml.NODE_ELEMENT,
  name: "a",
  filter: {
  and: [{
  type: gpf.xml.NODE_ATTRIBUTE,
  name: "d",
  text: "1"
  }]
  }
  },
  a
  _sample4 = {
  type: gpf.xml.NODE_ELEMENT,
  name: "a",
  relative: false
  }
  ;
   
  Internal helper to apply a function on a list of nodes.
  
  @param {gpf.xml.IXmlConstNode[]} nodes
  @param {Function} func
  @param {*} param
  @param {gpf.xml.IXmlConstNode[]} resultSet
  @private