docs: def set_upper_lower_bands(self,e_lower,e_upper):
          """
              Set fake upper/lower bands, useful to set the same energy
              range in the spin up/down bands when calculating the DOS
          """
          lower_band = e_lower*np.ones((1,self.ebands.shape[1]))
          upper_band = e_upper*np.ones((1,self.ebands.shape[1]))
  
          self.ebands = np.vstack((lower_band,self.ebands,upper_band))
          if isinstance(self.proj,np.ndarray):
              proj_lower = self.proj[:,0:1,:,:]
              proj_upper = self.proj[:,-1:,:,:]
              self.proj = np.concatenate((proj_lower,self.proj,proj_upper),axis=1)