code: def load_trajectory(self,trajectory):
          
  
          try:
              self.universe.load_new(trajectory)
          except IOError, ValueError:
              print "Check you trajectory file " + trajectory +"- it might be missing or misspelled."
docs: Loads the trajectory files e.g. XTC, DCD, TRJ together with the topology
          file as a MDAnalysis Universe. This will only be run if a trajectory has
          been submitted for analysis.
              Takes:
                  * topology * - a topology file e.g. GRO, PDB, INPCRD, CARD, DMS
                  * trajectory * - a trajectory file e.g. XTC, DCD, TRJ
              Output:
                  * self.universe * - an MDAnalysis Universe consisting from the
                  topology and trajectory file.