class_docstr: Tick formatter for a longitude axis.
class_docstr_tok: ["Tick","formatter","for","a","longitude","axis","."]
code: def _apply_transform(self, value, target_proj, source_crs):
      return target_proj.transform_point(value, 0, source_crs)[0]
  
imports: import matplotlib
  from matplotlib.ticker import Formatter, MaxNLocator
  import numpy
  import cartopy.crs
  from cartopy.mpl.geoaxes import GeoAxes
label_desc: Use image node_id 2 for calling the LongitudeFormatter obj's underlying member method code with example usage: obj._apply_transform(value, target_proj, source_crs) and returns: target_proj