code: def get_gridlines(self, which="major", axis="both"):
      grid_lines = []
      if axis in ["both", "x"]:
          for gl in self._grid_info["lon"]["lines"]:
              grid_lines.extend(gl)
      if axis in ["both", "y"]:
          for gl in self._grid_info["lat"]["lines"]:
              grid_lines.extend(gl)
      return grid_lines
  
imports: import functools
  from itertools import chain
  import numpy
  import matplotlib
  from matplotlib.path import Path
  from matplotlib.transforms import Affine2D, IdentityTransform
  from .axislines import _FixedAxisArtistHelperBase, _FloatingAxisArtistHelperBase, GridHelperBase
  from .axis_artist import AxisArtist
  from .grid_finder import GridFinder
label_desc: Use image node_id 6 for calling the GridHelperCurveLinear obj's underlying member method code with example usage: obj.get_gridlines(which, axis) and returns: grid_lines