func (t TokenBuilder) EqValue() Cmp {
	return t.valueCmp(eq, "")
}
EqValue produces token(column)=?
package qb
import (
	"fmt"
	"strings"
)
type TokenBuilder []string
func Token(columns ...string) TokenBuilder {
	return columns
}
func (t TokenBuilder) Eq() Cmp {
	return t.cmp(eq, nil)
}