code: def get_tile_rgb(tile_source, bbox, zoom_level, bbox_crs=None):
      """
      Returns an RGB element given a tile_source, bounding box and zoom level.
  
      Parameters
      ----------
      tile_source: WMTS element or string URL
        The tile source to download the tiles from.
      bbox: tuple
        A four tuple specifying the (left, bottom, right, top) corners of the
        domain to download the tiles for.
      zoom_level: int
        The zoom level at which to download the tiles
      bbox_crs: ccrs.CRs
        cartopy CRS defining the coordinate system of the supplied bbox
  
      Returns
      -------
      RGB element containing the tile data in the specified bbox
      """
  
      from .element import RGB, WMTS
  
      if bbox_crs is None:
          bbox_crs = ccrs.PlateCarree()
  
      if isinstance(tile_source, (WMTS, Tiles)):
          tile_source = tile_source.data
  
      if bbox_crs is not ccrs.GOOGLE_MERCATOR:
          bbox = project_extents(bbox, bbox_crs, ccrs.GOOGLE_MERCATOR)
  
      if "{Q}" in tile_source:
          tile_source = QuadtreeTiles(
              url=tile_source.replace("{Q}", "{tile}")
          )
      else:
          tile_source = GoogleTiles(url=tile_source)
  
      bounds = box(*bbox)
      rgb, extent, orient = tile_source.image_for_domain(
          bounds, zoom_level
      )
      if orient == "lower":
          rgb = rgb[::-1]
      x0, x1, y0, y1 = extent
      l, b, r, t = bbox
      return RGB(
          rgb,
          bounds=(x0, y0, x1, y1),
          crs=ccrs.GOOGLE_MERCATOR,
          vdims=["R", "G", "B"],
      ).clone(datatype=["grid", "xarray", "iris"])[l:r, b:t]
  
imports: import warnings
  import numpy
  import shapely
  import shapely.geometry
  from cartopy import crs
  from cartopy.io.img_tiles import GoogleTiles, QuadtreeTiles
  from holoviews.element import Tiles
  from packaging.version import Version
  from shapely.geometry import LinearRing, LineString, MultiLineString, MultiPoint, MultiPolygon, Point, Polygon, box
  from shapely.geometry.base import BaseMultipartGeometry
  from shapely.ops import transform
  from ._warnings import deprecated, warn
label_desc: Use image node_id 21 for calling a global function with example usage: get_tile_rgb(tile_source, bbox, zoom_level, bbox_crs) and returns: RGB