type Type struct {
Field map[string]string // map field name to type
Method map[string]string // map method name to comma-separated return types (should start with "func ")
Embed []string // list of types this type embeds (for extra methods)
Def string // definition of named type
}
Type describes the Fields and Methods of a type.
If the field or method cannot be found there, it is next
looked for in the Embed list.