code: def merge(*style_dicts):
      """
      Merge together multiple matplotlib style dictionaries in a predictable way
  
      The approach taken is:
  
          For each style:
              * Expand aliases, such as "lw" -> "linewidth", but always prefer
                the full form if over-specified (i.e. lw AND linewidth
                are both set)
              * "color" overwrites "facecolor" and "edgecolor" (as per
                matplotlib), UNLESS facecolor == "never", which will be expanded
                at finalization to 'none'
  
      >>> style = merge({"lw": 1, "edgecolor": "black", "facecolor": "never"},
      ...               {"linewidth": 2, "color": "gray"})
      >>> sorted(style.items())
      [('edgecolor', 'gray'), ('facecolor', 'never'), ('linewidth', 2)]
  
      """
      style = {}
      facecolor = None
  
      for orig_style in style_dicts:
          this_style = orig_style.copy()
  
          for alias_from, alias_to in _ALIASES.items():
              alias = this_style.pop(alias_from, None)
              if alias_from in orig_style:
                  # n.b. alias_from doesn't trump alias_to
                  # (e.g. 'lw' doesn't trump 'linewidth').
                  this_style.setdefault(alias_to, alias)
  
          color = this_style.pop("color", None)
          if "color" in orig_style:
              this_style["edgecolor"] = color
              this_style["facecolor"] = color
  
          if isinstance(facecolor, str) and facecolor == "never":
              requested_color = this_style.pop("facecolor", None)
              setting_color = not (
                  isinstance(requested_color, str)
                  and requested_color.lower() == "none"
              )
              if (
                  "fc" in orig_style or "facecolor" in orig_style
              ) and setting_color:
                  warnings.warn(
                      "facecolor will have no effect as it has been "
                      'defined as "never".'
                  )
          else:
              facecolor = this_style.get("facecolor", facecolor)
  
          # Push the remainder of the style into the merged style.
          style.update(this_style)
  
      return style
  
label_desc: Use image node_id 1 for calling a global function with example usage: merge() and returns: style