static TypeSignature ofBase(String baseTypeName) {
        checkBaseTypeName(baseTypeName, "baseTypeName");
        return new DefaultTypeSignature(TypeSignatureType.BASE, baseTypeName);
    }
Creates a new type signature for a base type.

@throws IllegalArgumentException if the specified type name is not valid
core/src/main/java/com/linecorp/armeria/server/docs/TypeSignature.java