@JvmOverloads fun set(value: Any, isDefault: Boolean = false): Unit
Set a value at the document's key defined by the preceding subscripting.
value - the value to set at the subscripting-defined document key.
isDefault - represents whether or not the value should be set as a default value. Set this to true if you want to set a default value that you expect to be overwritten by other devices in the network. The default value is false.
DittoError - Thrown if trying to update the document at an invalid key.