code: def _evoked_sensor_legend(
      info, picks, ymin, ymax, show_sensors, ax, sphere
  ):
      """Show sensor legend (location of a set of sensors on the head)."""
      if show_sensors is True:
          ymin, ymax = np.abs(ax.get_ylim())
          show_sensors = "lower right" if ymin > ymax else "upper right"
  
      pos, outlines = _get_pos_outlines(info, picks, sphere=sphere)
      show_sensors = _check_loc_legal(show_sensors, "show_sensors")
      _plot_legend(
          pos,
          ["k"] * len(picks),
          ax,
          list(),
          outlines,
          show_sensors,
          size=25,
      )
  
imports: from copy import deepcopy
  from functools import partial
  from itertools import cycle
  from numbers import Integral
  import numpy
  from .._fiff.pick import _DATA_CH_TYPES_SPLIT, _PICK_TYPES_DATA_DICT, _VALID_CHANNEL_TYPES, _picks_to_idx, channel_indices_by_type, channel_type, pick_info
  from ..defaults import _handle_default
  from ..fixes import _is_last_row
  from ..utils import _check_ch_locs, _check_if_nan, _clean_names, _is_numeric, _pl, _to_rgb, _validate_type, fill_doc, logger, verbose, warn
  from .topo import _plot_evoked_topo
  from .topomap import _check_sphere, _draw_outlines, _get_pos_outlines, _make_head_outlines, _prepare_topomap, _prepare_topomap_plot, _set_contour_locator, plot_topomap
  from .utils import DraggableColorbar, _check_cov, _check_delayed_ssp, _check_option, _check_time_unit, _draw_proj_checkbox, _get_cmap, _get_color_list, _make_combine_callable, _plot_masked_image, _prepare_joint_axes, _process_times, _prop_kw, _set_title_multiple_electrodes, _set_window_title, _setup_ax_spines, _setup_cmap, _setup_plot_projector, _setup_vmin_vmax, _triage_rank_sss, _trim_ticks, _validate_if_list_of_axes, plt_show
label_desc: Use image node_id 27 for calling a global function with example usage: _evoked_sensor_legend(info, picks, ymin, ymax, show_sensors, ax, sphere) without return types