kubernetes/vendor/google.golang.org/protobuf/proto/extension.go

// HasExtension reports whether an extension field is populated.
// It returns false if m is invalid or if xt does not extend m.
func HasExtension(m Message, xt protoreflect.ExtensionType) bool { … }

// ClearExtension clears an extension field such that subsequent
// [HasExtension] calls return false.
// It panics if m is invalid or if xt does not extend m.
func ClearExtension(m Message, xt protoreflect.ExtensionType) { … }

// GetExtension retrieves the value for an extension field.
// If the field is unpopulated, it returns the default value for
// scalars and an immutable, empty value for lists or messages.
// It panics if xt does not extend m.
func GetExtension(m Message, xt protoreflect.ExtensionType) any { … }

// SetExtension stores the value of an extension field.
// It panics if m is invalid, xt does not extend m, or if type of v
// is invalid for the specified extension field.
func SetExtension(m Message, xt protoreflect.ExtensionType, v any) { … }

// RangeExtensions iterates over every populated extension field in m in an
// undefined order, calling f for each extension type and value encountered.
// It returns immediately if f returns false.
// While iterating, mutating operations may only be performed
// on the current extension field.
func RangeExtensions(m Message, f func(protoreflect.ExtensionType, any) bool) { … }