code: function padTo(n, len) {
    assertIsBuffer(n, "n");
    var padding = len - n.length;
    assert_(padding > -1, "Negative padding.  Very uncomfortable.");
    var result = new Buffer(len);
    result.fill(0, 0, padding);
    n.copy(result, padding);
    assert.equal(result.length, len);
    return result;
  }
docs: /*
  If a conversion is explicitly specified with the operator PAD(),
  the integer will first be implicitly converted, then the resultant
  byte-string will be left-padded with zeros (if necessary) until its
  length equals the implicitly-converted length of N.
  
  params:
  n (buffer)       Number to pad
  len (int)        length of the resulting Buffer
  
  returns: buffer