docstr: Write value to mutable tensor with a synchronous API.
  
  Parameters
  ----------
  index:
      Index to write to the tensor.
  
  value:
      The value that will be filled into the mutable tensor according to `index`.
docstr_tok: ["Write","value","to","mutable","tensor","with","a","synchronous","API",".","Parameters","--","--","--","--","--","index",":","Index","to","write","to","the","tensor",".","value",":","The","value","that","will","be","filled","into","the","mutable","tensor","according","to","`","index","`","."]
code: def __setitem__(self, index, value):
      """
      Write value to mutable tensor with a synchronous API.
  
      Parameters
      ----------
      index:
          Index to write to the tensor.
  
      value:
          The value that will be filled into the mutable tensor according to `index`.
      """
      coro = self.write(index, value)
      fut = asyncio.run_coroutine_threadsafe(coro, self._loop)
      return fut.result()
  
file_path: mars/mars/services/mutable/core.py
imports: import asyncio
label_desc: Use image node_id 8 for calling the MutableTensor obj's underlying member method code with example usage: obj.__setitem__(index, value) and returns: fut