func (mf MinFee) Validate() error {
	if mf.MessageType == "" {
		return fmt.Errorf("invalid minimum fee message type")
	}
	if !mf.Amount.IsValid() {
		return fmt.Errorf("invalid minimum fee amount")
	}
	return nil
}
Validate checks if mf represents a valid instance
package types
import (
	"fmt"
	sdk "github.com/cosmos/cosmos-sdk/types"
)
func NewMinFee(messageType string, amount sdk.Coins) MinFee {
	return MinFee{
		MessageType: messageType,
		Amount:      amount,
	}
}