code: function context(newContext) {
    if (!_isUndefined(newContext)) {
      _previousContext = _context
      if (!_isArray(newContext)) {
        newContext = [newContext]
      }
      _context = newContext
    }
    return _context
  }
docs: Set's then returns genie's current context.
  If no context is provided, simply acts as getter.
  If a context is provided, genie's previous context
  is set to the context before it is assigned
  to the given context.
  @param {string|Array.<string>} newContext The context to set genie's context to.
  @returns {Array.<string>} The new context
  @public