code: function init (spec, defs, envs) {
    for (var key in spec || {}) {
      if (spec[key].def) defs[key] = spec[key].def
      if (has(spec[key].env)) envs[key] = get(spec[key].env)
    }
  }
docs: Initialize defaults and environment variables.
  
  @param {String} spec
  Parameters definition object.
  
  @param {Object} defs
  Default values container.
  
  @param {String} spec
  Environment values container.