Update NixRawIO to strictly follow RawIO data structure

neo/io/nixio_fr.py

@@ -1,5 +1,6 @@
 from neo.io.basefromrawio import BaseFromRaw
 from neo.rawio.nixrawio import NIXRawIO
+import warnings
 
 # This class subjects to limitations when there are multiple asymmetric blocks
 
@@ -11,10 +12,29 @@ class NixIO(NIXRawIO, BaseFromRaw):
     _prefered_signal_group_mode = 'group-by-same-units'
     _prefered_units_group_mode = 'all-in-one'
 
-    def __init__(self, filename):
-        NIXRawIO.__init__(self, filename)
+    def __init__(self, filename, block_index=0, autogenerate_stream_names=False, autogenerate_unit_ids=False):
+        NIXRawIO.__init__(self, filename,
+                          block_index=block_index,
+                          autogenerate_stream_names=autogenerate_stream_names,
+                          autogenerate_unit_ids=autogenerate_unit_ids)
         BaseFromRaw.__init__(self, filename)
 
+    def read_block(self, block_index=0, **kwargs):
+        # sanity check to ensure constructed header and block to load match
+        if block_index != 0:
+            raise ValueError(f'Initialized IO for block {self.block_index}. '
+                             f'Can only read that block. Ignoring additional {block_index=} argument.')
+
+        return super(NixIO, self).read_block(block_index=0, **kwargs)
+
+    def read_segment(self, block_index=0, **kwargs):
+        # sanity check to ensure constructed header and block to load match
+        if block_index != 0:
+            raise ValueError(f'Initialized IO for block {self.block_index}.'
+                             f'Can only read that block. Ignoring additional {block_index=} argument.')
+
+        return super(NixIO, self).read_segment(block_index=0, **kwargs)
+
     def __enter__(self):
         return self