ethclient: add PeerCount method ethereum#24849 (#1370)

Author: gzliudan

ethclient/ethclient.go

@@ -97,6 +97,13 @@ func (ec *Client) BlockNumber(ctx context.Context) (uint64, error) {
 	return uint64(result), err
 }
 
+// PeerCount returns the number of p2p peers as reported by the net_peerCount method.
+func (ec *Client) PeerCount(ctx context.Context) (uint64, error) {
+	var result hexutil.Uint64
+	err := ec.c.CallContext(ctx, &result, "net_peerCount")
+	return uint64(result), err
+}
+
 // BlockReceipts returns the receipts of a given block number or hash
 func (ec *Client) BlockReceipts(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash) ([]*types.Receipt, error) {
 	var r []*types.Receipt