 1-pole output').beCloseToArray(expected, {
                absoluteThreshold: 2.7657e-8
              });
            })
            .then(() => task.done());
      });

      // Return a function suitable for use as a defineTask function.  This
      // function creates an IIRFilterNode equivalent to the specified
      // BiquadFilterNode and compares the outputs.  The outputs from the two
      // filters should be virtually identical.
      function testWithBiquadFilter(filterType, errorThreshold, snrT