code: def load_stl(file_obj, file_type=None, **kwargs):
      
      # save start of file obj
      file_pos = file_obj.tell()
      try:
          # check the file for a header which matches the file length
          # if that is true, it is almost certainly a binary STL file
          # if the header doesn't match the file length a HeaderError will be
          # raised
          return load_stl_binary(file_obj)
      except HeaderError:
          # move the file back to where it was initially
          file_obj.seek(file_pos)
          # try to load the file as an ASCII STL
          # if the header doesn't match the file length a HeaderError will be
          # raised
          return load_stl_ascii(file_obj)
docs: Load an STL file from a file object.
  
      Parameters
      ----------
      file_obj: open file- like object
      file_type: not used
  
      Returns
      ----------
      loaded: kwargs for a Trimesh constructor with keys:
                vertices:     (n,3) float, vertices
                faces:        (m,3) int, indexes of vertices
                face_normals: (m,3) float, normal vector of each face