(self, x)
return x
x shape :[ batch, time, dim]
      output shape: [batch, dim]
x shape :[ batch, time, dim]
      output shape: [batch, dim]
x shape : [ batch time dim ] output shape : [ batch dim ]
def call(self, x):
    '''
      x shape :[ batch, time, dim]
      output shape: [batch, dim]
    '''
    x = self.time_pool(x)
    x = self.reshape(x)
    return x
def call ( self , x ) : x = self . time_pool ( x ) x = self . reshape ( x ) return x