func CustomNamer(namer TypeNamer) ExtractOption {
	return func(e *extractor) {
		e.typeNamer = namer
	}
}
CustomNamer sets a custom function for translating Golang naming convention
to Typescript naming convention. This function does not have to translate
the type names, just the way they are written.
package bel
import (
	"fmt"
	"reflect"
	"sort"
	"strings"
	"github.com/iancoleman/strcase"
)
type ExtractOption func(*extractor)
type AnonStructNamer func(reflect.StructField) string
type TypeNamer func(reflect.Type) string
type extractor struct {
	embedStructs    bool
	followStructs   bool
	noAnonStructs   bool
	sorter          func(a, b interface{}) bool
	anonStructNamer AnonStructNamer
	typeNamer       TypeNamer
	enumHandler     EnumHandler
	docHandler      DocHandler
	result map[string]TypescriptType
}
func EmbedStructs(e *extractor) {
	e.embedStructs = true
	e.followStructs = true
}
func FollowStructs(e *extractor) {
	e.followStructs = true
}
func NameAnonStructs(namer AnonStructNamer) ExtractOption {
	return func(e *extractor) {
		e.noAnonStructs = true
		e.anonStructNamer = namer
	}
}