Undocumented

• lPush() --> Insert elements at the begin of the list.
• rPush() --> Insert elements at the end of the list.
• lPop() --> Returns elements at the begin of the list and removes them.
• rPop() --> Returns elements at the end of the list and removes them.
• lIndex() --> Returns the element at the specified index of the list.
• lLen() --> Returns the length of the list.
• lSet() --> Updates the element at the specified index of the list.