code: def assertpathsandfiles(self):
          
          # Assertion to ensure that the MiSeq path exists
          assert os.path.isdir(self.miseqpath), u'MiSeqPath is not a valid directory {0!r:s}'.format(self.miseqpath)
          # If the miseq folder name is not provided, the default of the most recent run will be used
          if not self.miseqfolder:
              # Get a list of folders
              miseqfolders = glob('{}*/'.format(self.miseqpath))
              self.miseqfolder = sorted(miseqfolders)[-1]
              # Create :miseqfoldername to store the name of this folder by splitting the path and taking the second
              # last piece (it's not the last piece because the folder has a trailing slash)
              self.miseqfoldername = self.miseqfolder.split("/")[-2]
          # Otherwise add the folder to the miseq path to yield the destination folder
          else:
              # Set the folder name before adding the path to the miseq path
              self.miseqfoldername = self.miseqfolder
              self.miseqfolder = self.miseqpath + self.miseqfolder + "/"
              # Assert to ensure that the folder exists
              assert os.path.isdir(self.miseqfolder), u'MiSeqFolder is not a valid directory {0!r:s}'\
                  .format(self.miseqfolder)
          # Pull the data from the SampleSheet.csv
          if self.customsamplesheet:
              self.samplesheet = self.customsamplesheet
              assert os.path.isfile(self.customsamplesheet), u'Could not find CustomSampleSheet as entered: {0!r:s}'\
                  .format(self.customsamplesheet)
          # Otherwise use the SampleSheet.csv located in :self.miseqfolder
          else:
              self.samplesheet = self.miseqfolder + "SampleSheet.csv"
docs: Assertions to make sure that arguments are at least mostly valid