def METHOD_NAME(n_obs, n_var, p_zero, p_nan):
    """
    creates an AnnData with random data, sparseness and some NaN values
    """
    X = _create_sparse_nan_matrix(n_obs, n_var, p_zero, p_nan)
    adata = AnnData(X)
    gene_names = _create_random_gene_names(n_var, name_length=6)
    adata.var_names = gene_names
    return adata