+Writes up to the specified amount of bytes using the data of {\it buffer}. Note
+that not all data can always be written so you must check the number of bytes
+really written to the stream using \helpref{LastWrite()}{wxoutputstreamlastwrite}
+when this function returns. In some cases (for example a write end of a pipe
+which is currently full) it is even possible that there is no errors and zero
+bytes have been written.
+
+This function returns a reference on the current object, so the user can test
+any states of the stream right away.