// A Client is an HTTP client. Its zero value (DefaultClient) is a usable client
// that uses DefaultTransport.
+//
+// The Client's Transport typically has internal state (cached
+// TCP connections), so Clients should be reused instead of created as
+// needed. Clients are safe for concurrent use by multiple goroutines.
+//
// Client is not yet very configurable.
type Client struct {
Transport RoundTripper // if nil, DefaultTransport is used
// RoundTripper is an interface representing the ability to execute a
// single HTTP transaction, obtaining the Response for a given Request.
+//
+// A RoundTripper must be safe for concurrent use by multiple
+// goroutines.
type RoundTripper interface {
// RoundTrip executes a single HTTP transaction, returning
// the Response for the request req. RoundTrip should not