code: def _build_qual_histogram(data):
      """Create the Quality(QUAL) histogram."""
      width = 200
      height = 200
      title = "Quality score"
      qual_data = pd.DataFrame(data)
      qual_histogram = _placeholder_for_empty_chart(
          "No entries in VCF", width=width, height=height, title=title
      )
      if not qual_data.empty:
          # s = bin_start, e = bin_end, c = count
          domain = [min(0, data[0]["s"]), max(150, data[-1]["e"])]
          qual_histogram = (
              alt.Chart(qual_data)
              .mark_bar(color=BAR_COLOR_QUAL)
              .encode(
                  x=alt.X(
                      "s", title="QUAL", scale=alt.Scale(domain=domain)
                  ),
                  x2="e",
                  y=alt.Y(
                      "c",
                      title="Count",
                      stack=True,
                      axis=alt.Axis(format="s"),
                  ),
              )
              .properties(width=width, height=height, title=title)
              .interactive(bind_y=False)
          )
      return qual_histogram
  
imports: import io
  import json
  import os
  import altair
  import numpy
  import pandas
  import tensorflow
label_desc: Use image node_id 4 for calling a global function with example usage: _build_qual_histogram(data) and returns: qual_histogram