The interface for all 
    
    Property objects that define a world
location as a Cartesian3 with an associated ReferenceFrame.
This type defines an interface and cannot be instantiated directly.
Members
readonly definitionChanged : Event
    Gets the event that is raised whenever the definition of this property changes.
The definition is considered to have changed if a call to getValue would return
a different result for the same time.
    Gets a value indicating if this property is constant.  A property is considered
constant if getValue always returns the same result for the current definition.
referenceFrame : ReferenceFrame
    Gets the reference frame that the position is defined in.
Methods
    Compares this property to the provided property and returns
    
true if they are equal, false otherwise.
| Name | Type | Description | 
|---|---|---|
| other | Property | optional The other property. | 
Returns:
true if left and right are equal, false otherwise.
getValue(time, result) → Cartesian3|undefined
    Gets the value of the property at the provided time in the fixed frame.
    
| Name | Type | Description | 
|---|---|---|
| time | JulianDate | The time for which to retrieve the value. | 
| result | Cartesian3 | optional The object to store the value into, if omitted, a new instance is created and returned. | 
Returns:
    The modified result parameter or a new instance if the result parameter was not supplied.
    
getValueInReferenceFrame(time, referenceFrame, result) → Cartesian3|undefined
    Gets the value of the property at the provided time and in the provided reference frame.
    
| Name | Type | Description | 
|---|---|---|
| time | JulianDate | The time for which to retrieve the value. | 
| referenceFrame | ReferenceFrame | The desired referenceFrame of the result. | 
| result | Cartesian3 | optional The object to store the value into, if omitted, a new instance is created and returned. | 
Returns:
    The modified result parameter or a new instance if the result parameter was not supplied.
    
