code: function (key, value) {
          'use strict';
          var obj;
          if (!isStr(key)) {
              throw new Error(confKeyStrMsg, 'config-manager');
          }
          if (key.indexOf('.') === -1) {
              conf[key] = value;
          } else {
              obj = getLastNodeKey(key, conf);
              obj.node[obj.key] = value;
          }
          return this;
      }
docs: Set 'value' for 'key'
  @param {string} key - key in configuration. Like 'simpleKey' or 'section.subsection.complex.key'. See config-managet-test.js
  @param {*} value