Server-Entity: Momentary Rotating Door/Lever/Valve. 
QUAKED momentary_rot_button (0 .5 .8) ? MRBFL_DOORHACK MRBFL_NOTUSE x x MRBFL_AUTORETURN x MRBFL_XAXIS MRBFL_YAXIS 
OVERVIEW
Dyanmic button/wheel/lever that moves back into its original position when not in use. It affects momentary_door.
KEYS
- "targetname" : Name
- "distance" : Maximum distance it'll turn until it stops.
- "speed" : Speed at which it rotates/turns.
- "returnspeed" : Speed at which it returns to its original position.
SPAWNFLAGS
- MRBFL_DOORHACK (1) : This entity will move along with another momentary_rot_button of the same name.
- MRBFL_NOTUSE (2) : Don't allow interaction via "use" key/button.
- MRBFL_AUTORETURN (16) : Rotate back to its original state when not being used.
- MRBFL_XAXIS (64) : Rotate along the X-axis.
- MRBFL_YAXIS (128) : Rotate along the Y-axis.
TRIVIA
This entity was introduced in Half-Life (1998). 
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| void | momentary_rot_button (void) | 
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| virtual void | Save (float) | 
|  | Handles saving a copy of this entity to a given filehandle. 
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| virtual void | Restore (string, string) | 
|  | Similar to ncIO::SpawnKey() but for save-game fields. 
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| virtual void | OnPlayerUse (void) | 
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| virtual void | OnPlayerUnUse (void) | 
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| virtual void | Respawn (void) | 
|  | Server: Called when the entity first spawns or when game-logic requests the entity to return to its original spawn state. 
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| virtual void | SetMovementDirection (void) | 
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| virtual void | SpawnKey (string, string) | 
|  | This method handles entity key/value pairs on map load. 
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| virtual void | MovementDone (void) | 
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| virtual void | MovementStateChanged (void) | 
|  | Called whenever the movement state changes. 
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| virtual float | GetProgress (void) | 
|  | Returns the progress of the momentary, which is a value between 0.0 and 1.0. 
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