message: Add test for privateKeyBufferFromECPair
  Try to bump up coverage above 90% again.
diff: @@ -29,6 +29,12 @@ describe('privateKeyBufferFromECPair', function () {
  assert.strictEqual(privateKeyBufferFromECPair(keyPair).length, 32)
  assert.strictEqual(privateKeyBufferFromECPair(keyPair).toString('hex'), hexString)
  })
  +
  + it('throws if passed value is not ecpair', function () {
  + assert.throws(function () {
  + privateKeyBufferFromECPair({})
  + }, new RegExp('invalid argument ecpair'))
  + })
  })
  describe('privateKeyBufferToECPair', function () {
  