code: func (wc *WhisperClient) SetMinimumPoW(ctx *Context, pow float64) error {
  	return wc.client.SetMinimumPoW(ctx.context, pow)
  }
docs: // SetMinimumPoW (experimental) sets the minimal PoW required by this node.
  // This experimental function was introduced for the future dynamic adjustment of
  // PoW requirement. If the node is overwhelmed with messages, it should raise the
  // PoW requirement and notify the peers. The new value should be set relative to
  // the old value (e.g. double). The old value could be obtained via shh_info call.