Speaking of missing... this should have been included in the manual, you'll probably find it helpful:

ValueOperation Methods

    DeleteKey :
        Deletes the key/value pair at the given index for a key valueOp. Returns 1 if the key was deleted, returns 0 if no key exists at the given index or the valueOp is not of type kValueOpTypeCodeKEY.
        DeleteKey( index)

    Delta :
        Get the delta value of a deltaAdd value operation. Returns 0 if the value operation is not of type kValueOpTypeCodeDELTAADD.
        Delta()

    GetKey :
        Returns a tuple containing the key and value at the given index for a key valueOp.
        (, ) GetKey( index)

    InsertKey :
        Inserts a key/value pair in this key valueOp. Returns 1 if the key was inserted, returns 0 if the valueOp is not of type kValueOpTypeCodeKEY.
        InsertKey( key, value)

    NumKeys :
        Get the number of keys of a key value operation. Returns -1 if the value operation is not of type kValueOpTypeCodeKEY.
        NumKeys()

    Parameter :
        Get the parameter associated with this valueOp.
        Parameter()

    SetDelta :
        Set the delta value of a deltaAdd value operation.
        SetDelta( delta)

    SetSourceParameter :
        Set the source paramater associated with this value operation.
        SetSourceParameter( source)

    SourceParameter :
        Get the source parameter associated with this valueOp.
        SourceParameter()

    Type :
        Get the type of the valueOp.
        Type()