code: def append(self, data, axis=0):
          
          return self._write_op(self._append_nosync, data, axis=axis)
docs: Append `data` to `axis`.
  
          Parameters
          ----------
          data : array_like
              Data to be appended.
          axis : int
              Axis along which to append.
  
          Returns
          -------
          new_shape : tuple
  
          Notes
          -----
          The size of all dimensions other than `axis` must match between this
          array and `data`.
  
          Examples
          --------
          >>> import numpy as np
          >>> import zarr
          >>> a = np.arange(10000000, dtype='i4').reshape(10000, 1000)
          >>> z = zarr.array(a, chunks=(1000, 100))
          >>> z.shape
          (10000, 1000)
          >>> z.append(a)
          (20000, 1000)
          >>> z.append(np.vstack([a, a]), axis=1)
          (20000, 2000)
          >>> z.shape
          (20000, 2000)