==========================
Simple Pie chart
==========================

pie
    title Key elements in Product X
    "Calcium" : 42.96
    "Potassium" : 50.05
    "Magnesium" : 10.01
    "Iron" :  5

---

(source_file
  (diagram_pie
    (pie_stmt_title
      (pie_title))
    (pie_stmt_element
      (pie_label)
      (pie_value))
    (pie_stmt_element
      (pie_label)
      (pie_value))
    (pie_stmt_element
      (pie_label)
      (pie_value))
    (pie_stmt_element
      (pie_label)
      (pie_value))))
