code: def from_set(self, fileset, check_if_dicoms=True):
          
          if check_if_dicoms:
              self.items = []
              for f in fileset:
                  if is_dicom_file(f):
                      self.items.append(f)
          else:
              self.items = fileset
docs: Overwrites self.items with the given set of files.
          Will filter the fileset and keep only Dicom files.
  
          Parameters
          ----------
          fileset: iterable of str
          Paths to files
  
          check_if_dicoms: bool
          Whether to check if the items in fileset are dicom file paths