assignment mismatch: 2 variables but ecdsa.SignCompact returns 1 value

cannot use (*immutableTree)(nil) (value of type *immutableTree) as Tree value in variable declaration: *immutableTree does not implement Tree (wrong type for method Iterator)

cannot use (*iavl.MutableTree)(nil) (value of type *"github.com/cosmos/iavl".MutableTree) as Tree value in variable declaration: *"github.com/cosmos/iavl".MutableTree does not implement Tree (wrong type for method Iterator)

cannot use db (variable of type store.KVStoreWithBatch) as "github.com/cosmos/iavl/db".DB value in argument to iavl.NewMutableTree: store.KVStoreWithBatch does not implement "github.com/cosmos/iavl/db".DB (wrong type for method Iterator)

cannot use tree (variable of type *"github.com/cosmos/iavl".MutableTree) as Tree value in struct literal: *"github.com/cosmos/iavl".MutableTree does not implement Tree (wrong type for method Iterator)

cannot use tree (variable of type *"github.com/cosmos/iavl".MutableTree) as Tree value in struct literal: *"github.com/cosmos/iavl".MutableTree does not implement Tree (wrong type for method Iterator)

cannot use &immutableTree{…} (value of type *immutableTree) as Tree value in struct literal: *immutableTree does not implement Tree (wrong type for method Iterator)

impossible type assertion: istore.tree.(*immutableTree)

impossible type assertion: st.tree.(*iavl.MutableTree)