mu.pp.filter_obs(mdata, 'n_genes_by_counts', lambda x: (x >= 100))mu.pp.filter_obs(mdata,  'total_counts', lambda x: (x >= 500) & (x <= 50000)

muon/_core/preproc.py in filter_obs(data, var, func)    733         # filter_obs() for each modality    734         for m, mod in data.mod.items():--> 735             obsmap = data.obsmap[m][obs_subset]    736             obsmap = obsmap[obsmap != 0] - 1    737             filter_obs(mod, mod.obs_names[obsmap])anndata/_core/aligned_mapping.py in __getitem__(self, key)    146     147     def __getitem__(self, key: str) -> V:--> 148         return self._data[key]    149     150     def __setitem__(self, key: str, value: V):KeyError: 'x'

import numpy as npimport muon as mux = mu.AnnData(X=np.random.normal(size=1000).reshape(-1, 100))y = mu.AnnData(X=np.random.normal(size=2000).reshape(-1, 100))md = mu.MuData({"x": x, "y": y})md['x'].obs['total_count'] = md['x'].X.sum(axis=1)md['x'].obs['min_count'] = md['x'].X.min(axis=1)md.update()# filter one of the modalities.mu.pp.filter_obs(md, 'x:min_count', lambda x: (x < -2))mu.pp.filter_obs(md, 'x:total_count', lambda x: (x >0))