[Member name] DiffGram [Description] 
Reads a DiffGram, applying changes from the DiffGram to the DataSet. The semantics are identical to those of a Merge operation. As with the Merge operation, RowState values are preserved. Input to ReadXml with DiffGrams should only be obtained using the output from WriteXml as a DiffGram. The target DataSet must have the same schema as the DataSet on which WriteXml as DiffGram is called. Otherwise the DiffGram merge operation fails, and an exception is thrown.