code: function unpack$1(buffer, theType, index=0) {
    return unpackArray(
      buffer, theType, index, index + Math.ceil(theType.bits / 8), true)[0];
  }
docs: Unpack a number from a byte buffer.
  @param {!Uint8Array|!Array<number>} buffer The byte buffer.
  @param {!Object} theType The type definition.
  @param {number=} index The buffer index to read. Assumes zero if undefined.
  @return {number}
  @throws {Error} If the type definition is not valid
  @throws {Error} On bad buffer length.
  @throws {Error} On overflow