code: def process_crs(crs):
      """
      Parses cartopy CRS definitions defined in one of a few formats:
  
        1. EPSG codes:   Defined as string of the form "EPSG: {code}" or an integer
        2. proj.4 string: Defined as string of the form "{proj.4 string}"
        3. cartopy.crs.CRS instance
        3. pyproj.Proj or pyproj.CRS instance
        4. WKT string:    Defined as string of the form "{WKT string}"
        5. None defaults to crs.PlateCaree
      """
      missing = []
      try:
          import cartopy.crs as ccrs
      except ImportError:
          missing.append("cartopy")
      try:
          import geoviews as gv  # noqa
      except ImportError:
          missing.append("geoviews")
      try:
          import pyproj
      except ImportError:
          missing.append("pyproj")
      if missing:
          raise ImportError(
              f'Geographic projection support requires: {", ".join(missing)}.'
          )
  
      if crs is None:
          return ccrs.PlateCarree()
      elif isinstance(crs, ccrs.CRS):
          return crs
      elif isinstance(crs, pyproj.CRS):
          crs = crs.to_wkt()
  
      errors = []
      if isinstance(crs, (str, int)):  # epsg codes
          try:
              crs = pyproj.CRS.from_epsg(crs).to_wkt()
          except Exception as e:
              errors.append(e)
      if isinstance(crs, (str, pyproj.Proj)):  # proj4/wkt strings
          try:
              return proj_to_cartopy(crs)
          except Exception as e:
              errors.append(e)
  
      raise ValueError(
          "Projection must be defined as a EPSG code, proj4 string, "
          "WKT string, cartopy CRS, pyproj.Proj, or pyproj.CRS."
      ) from Exception(*errors)
  
imports: import sys
  from collections.abc import Hashable
  from functools import wraps
  from packaging.version import Version
  from types import FunctionType
  import bokeh
  import numpy
  import pandas
  import param
  import holoviews
label_desc: Use image node_id 6 for calling a global function with example usage: process_crs(crs) and returns: ccrs, crs, proj_to_cartopy