docstr: Computes the aspect ratio of the plot
code: def get_aspect(self, xspan, yspan):
      """
      Computes the aspect ratio of the plot
      """
      if isinstance(self.aspect, (int, float)):
          return self.aspect
      elif self.aspect == "square":
          return 1
      elif self.aspect == "equal":
          return xspan / yspan
      return 1
  
imports: import copy
  import math
  import warnings
  from types import FunctionType
  import matplotlib.colors
  import numpy
  import param
  from matplotlib import ticker
  from matplotlib.dates import date2num
  from matplotlib.image import AxesImage
  from packaging.version import Version
  from ...core import CompositeOverlay, Dataset, DynamicMap, Element, Element3D, NdOverlay, util
  from ...core.options import Keywords, abbreviated_exception
  from ...element import Graph, Path
  from ...streams import Stream
  from ...util.transform import dim
  from ..plot import GenericElementPlot, GenericOverlayPlot
  from ..util import color_intervals, dim_range_key, process_cmap
  from .plot import MPLPlot, mpl_rc_context
  from .util import EqHistNormalize, mpl_version, validate, wrap_formatter
label_desc: Use image node_id 9 for calling the ElementPlot obj's underlying member method code with example usage: obj.get_aspect(xspan, yspan) and returns: int, self, int, unknown