Method which will validate, using custom code supplied this class, the field with index fieldIndex if it should accept the specified value. This routine is only called when standard checks already succeeded, so value isn't null, and value does match the destination column definition of the EntityField related to fieldIndex.

protected virtual bool OnValidateFieldValue(
	int fieldIndex,
	Object value
)

Protected Overridable Function OnValidateFieldValue ( 
	fieldIndex As Integer,
	value As Object
) As Boolean