diff --git a/go/vendor/google.golang.org/grpc/vet.sh b/go/vendor/google.golang.org/grpc/vet.sh
new file mode 100755
index 0000000..eb32870
--- /dev/null
+++ b/go/vendor/google.golang.org/grpc/vet.sh
@@ -0,0 +1,129 @@
+#!/bin/bash
+
+if [[ `uname -a` = *"Darwin"* ]]; then
+  echo "It seems you are running on Mac. This script does not work on Mac. See https://github.com/grpc/grpc-go/issues/2047"
+  exit 1
+fi
+
+set -ex  # Exit on error; debugging enabled.
+set -o pipefail  # Fail a pipe if any sub-command fails.
+
+die() {
+  echo "$@" >&2
+  exit 1
+}
+
+# Check to make sure it's safe to modify the user's git repo.
+if git status --porcelain | read; then
+  die "Uncommitted or untracked files found; commit changes first"
+fi
+
+if [[ -d "${GOPATH}/src" ]]; then
+  die "\${GOPATH}/src (${GOPATH}/src) exists; this script will delete it."
+fi
+
+# Undo any edits made by this script.
+cleanup() {
+  rm -rf "${GOPATH}/src"
+  git reset --hard HEAD
+}
+trap cleanup EXIT
+
+PATH="${GOPATH}/bin:${GOROOT}/bin:${PATH}"
+
+if [[ "$1" = "-install" ]]; then
+  # Check for module support
+  if go help mod >& /dev/null; then
+    go install \
+      github.com/golang/lint/golint \
+      golang.org/x/tools/cmd/goimports \
+      honnef.co/go/tools/cmd/staticcheck \
+      github.com/client9/misspell/cmd/misspell \
+      github.com/golang/protobuf/protoc-gen-go
+  else
+    # Ye olde `go get` incantation.
+    # Note: this gets the latest version of all tools (vs. the pinned versions
+    # with Go modules).
+    go get -u \
+      github.com/golang/lint/golint \
+      golang.org/x/tools/cmd/goimports \
+      honnef.co/go/tools/cmd/staticcheck \
+      github.com/client9/misspell/cmd/misspell \
+      github.com/golang/protobuf/protoc-gen-go
+  fi
+  if [[ -z "${VET_SKIP_PROTO}" ]]; then
+    if [[ "${TRAVIS}" = "true" ]]; then
+      PROTOBUF_VERSION=3.3.0
+      PROTOC_FILENAME=protoc-${PROTOBUF_VERSION}-linux-x86_64.zip
+      pushd /home/travis
+      wget https://github.com/google/protobuf/releases/download/v${PROTOBUF_VERSION}/${PROTOC_FILENAME}
+      unzip ${PROTOC_FILENAME}
+      bin/protoc --version
+      popd
+    elif ! which protoc > /dev/null; then
+      die "Please install protoc into your path"
+    fi
+  fi
+  exit 0
+elif [[ "$#" -ne 0 ]]; then
+  die "Unknown argument(s): $*"
+fi
+
+git ls-files "*.go" | xargs grep -L "\(Copyright [0-9]\{4,\} gRPC authors\)\|DO NOT EDIT" 2>&1 | tee /dev/stderr | (! read)
+git ls-files "*.go" | xargs grep -l '"math/rand"' 2>&1 | (! grep -v '^examples\|^stress\|grpcrand') | tee /dev/stderr | (! read)
+git ls-files | xargs dirname | sort | uniq | xargs go run test/go_vet/vet.go | tee /dev/stderr | (! read)
+gofmt -s -d -l . 2>&1 | tee /dev/stderr | (! read)
+goimports -l . 2>&1 | tee /dev/stderr | (! read)
+golint ./... 2>&1 | (grep -vE "(_mock|\.pb)\.go:" || true) | tee /dev/stderr | (! read)
+
+# Rewrite golang.org/x/net/context -> context imports (see grpc/grpc-go#1484).
+# TODO: Remove this mangling once "context" is imported directly (grpc/grpc-go#711).
+git ls-files "*.go" | xargs sed -i 's:"golang.org/x/net/context":"context":'
+set +o pipefail # vet exits with non-zero error if issues are found
+
+# TODO(deklerk) remove when we drop Go 1.6 support
+go tool vet -all . 2>&1 | \
+    grep -vE 'clientconn.go:.*cancel (function|var)' | \
+    grep -vE '.*transport_test.go:.*cancel' | \
+    tee /dev/stderr | \
+    (! read)
+
+set -o pipefail
+git reset --hard HEAD
+
+if [[ -z "${VET_SKIP_PROTO}" ]]; then
+  PATH="/home/travis/bin:${PATH}" make proto && \
+    git status --porcelain 2>&1 | (! read) || \
+    (git status; git --no-pager diff; exit 1)
+fi
+
+if go help mod >& /dev/null; then
+  go mod tidy && \
+    git status --porcelain 2>&1 | (! read) || \
+    (git status; git --no-pager diff; exit 1)
+fi
+
+### HACK HACK HACK: Remove once staticcheck works with modules.
+# Make a symlink in ${GOPATH}/src to its ${GOPATH}/pkg/mod equivalent for every package we use.
+for x in $(find "${GOPATH}/pkg/mod" -name '*@*' | grep -v \/mod\/cache\/); do
+  pkg="$(echo ${x#"${GOPATH}/pkg/mod/"} | cut -f1 -d@)";
+  # If multiple versions exist, just use the existing one.
+  if [[ -L "${GOPATH}/src/${pkg}" ]]; then continue; fi
+  mkdir -p "$(dirname "${GOPATH}/src/${pkg}")";
+  ln -s $x "${GOPATH}/src/${pkg}";
+done
+### END HACK HACK HACK
+
+# TODO(menghanl): fix errors in transport_test.
+staticcheck -ignore '
+internal/transport/transport_test.go:SA2002
+benchmark/benchmain/main.go:SA1019
+stats/stats_test.go:SA1019
+test/end2end_test.go:SA1019
+balancer_test.go:SA1019
+balancer.go:SA1019
+clientconn_test.go:SA1019
+internal/transport/handler_server_test.go:SA1019
+internal/transport/handler_server.go:SA1019
+' ./...
+misspell -error .