tests: Add test for extended arguments to stream .write() method.

tests/io/write_ext.py

@@ -0,0 +1,25 @@
+import uio
+
+try:
+    uio.BytesIO
+except AttributeError:
+    import sys
+    print('SKIP')
+    sys.exit()
+
+buf = uio.BytesIO()
+
+buf.write(b"foo", 2)
+print(buf.getvalue())
+
+buf.write(b"foo", 100)
+print(buf.getvalue())
+
+buf.write(b"foobar", 1, 3)
+print(buf.getvalue())
+
+buf.write(b"foobar", 1, 100)
+print(buf.getvalue())
+
+buf.write(b"foobar", 100, 100)
+print(buf.getvalue())

tests/io/write_ext.py.exp

@@ -0,0 +1,5 @@
+b'fo'
+b'fofoo'
+b'fofoooob'
+b'fofooooboobar'
+b'fofooooboobar'