text: 'use strict';
  
  var Range = require('./internal/Range'),
      defineOnPrototype = require('../common/internal/defineOnPrototype');
  
  defineOnPrototype(Range, {
  
    'contains': function(el) {
      if (el == null) return false;
      if (el.start && el.end) {
        return el.start >= this.start && el.start <= this.end &&
               el.end   >= this.start && el.end   <= this.end;
      } else {
        return el >= this.start && el <= this.end;
      }
    }
  
  });
  
  // This package does not export anything as it is
  // simply defining "contains" on Range.prototype.