docs(invocation): edit (and finish) Go docs for exported types

token/invocation/invocation.go

@@ -57,7 +57,8 @@ type Token struct {
 // or to leave the nonce empty respectively.
 //
 // If no invokedAt is provided, the current time is used. Use the
-// WithInvokedAt or WithInvokedAtIn options to specify a different time.
+// WithInvokedAt or WithInvokedAtIn Options to specify a different time
+// or the WithoutInvokedAt Option to clear the Token's invokedAt field.
 //
 // With the exception of the WithMeta option, all other will overwrite
 // the previous contents of their target field.
@@ -113,10 +114,14 @@ func (t *Token) Command() command.Command {
 	return t.command
 }
 
+// Arguments returns the arguments to be used when the command is
+// invoked.
 func (t *Token) Arguments() map[string]datamodel.Node {
 	return t.arguments
 }
 
+// Proof() returns the ordered list of cid.Cids which referenced the
+// delegation Tokens that authorize this invocation.
 func (t *Token) Proof() []cid.Cid {
 	return t.proof
 }
@@ -136,11 +141,14 @@ func (t *Token) Expiration() *time.Time {
 	return t.expiration
 }
 
+// InvokedAt returns the time.Time at which the invocation token was
+// created.
 func (t *Token) InvokedAt() *time.Time {
 	return t.invokedAt
 }
 
-// Cause returns the (optional)
+// Cause returns the Token's (optional) cause field which may specify
+// which describes the Receipt that requested the invocation.
 func (t *Token) Cause() *cid.Cid {
 	return t.cause
 }

token/invocation/options.go

@@ -9,7 +9,7 @@ import (
 )
 
 // Option is a type that allows optional fields to be set during the
-// creation of a Token.
+// creation of a invocation Token.
 type Option func(*Token) error
 
 // WithArgument adds a key/value pair to the Token's Arguments field.
@@ -62,7 +62,9 @@ func WithMeta(key string, val any) Option {
 // WithNonce sets the Token's nonce with the given value.
 //
 // If this option is not used, a random 12-byte nonce is generated for
-// this require.
+// this required field.  If you truly want to create an invocation Token
+// without a nonce, use the WithEmptyNonce Option which will set the
+// nonce to an empty byte array.
 func WithNonce(nonce []byte) Option {
 	return func(t *Token) error {
 		t.nonce = nonce
@@ -95,12 +97,16 @@ func WithExpiration(exp time.Time) Option {
 
 // WithExpirationIn set's the Token's optional "expiration" field to
 // Now() plus the given duration.
-func WithExpirationIn(exp time.Duration) Option {
+func WithExpirationIn(after time.Duration) Option {
-	return WithExpiration(time.Now().Add(exp))
+	return WithExpiration(time.Now().Add(after))
 }
 
 // WithInvokedAt sets the Token's invokedAt field to the provided
 // time.Time.
+//
+// If this Option is not provided, the invocation Token's iat field will
+// be set to the value of time.Now().  If you want to create an invocation
+// Token without this field being set, use the WithoutInvokedAt Option.
 func WithInvokedAt(iat time.Time) Option {
 	return func(t *Token) error {
 		t.invokedAt = &iat