room/runtime/src/main/java/androidx/room/RoomDatabase.java
@SuppressWarnings("WeakerAccess")
        @Nullable
        public List<Migration> findMigrationPath(int start, int end) {
            if (start == end) {
                return Collections.emptyList();
            }
            boolean migrateUp = end > start;
            List<Migration> result = new ArrayList<>();
            return findUpMigrationPath(result, migrateUp, start, end);
        }
/**
         * Finds the list of migrations that should be run to move from {@code start} version to
         * {@code end} version.
         *
         * @param start The current database version
         * @param end   The target database version
         * @return An ordered list of {@link Migration} objects that should be run to migrate
         * between the given versions. If a migration path cannot be found, returns {@code null}.
         */
Finds the list of migrations that should be run to move from  start version to
end version.

@param start The current database version
@param end   The target database version
@return An ordered list of  Migration objects that should be run to migrate
between the given versions. If a migration path cannot be found, returns  null.
Finds the list of migrations that should be run to move from start version to end version . @param start The current database version @param end The target database version @return An ordered list of Migration objects that should be run to migrate between the given versions . If a migration path cannot be found returns null .
@SuppressWarnings("WeakerAccess")
        @Nullable
        public List<Migration> findMigrationPath(int start, int end) {
            if (start == end) {
                return Collections.emptyList();
            }
            boolean migrateUp = end > start;
            List<Migration> result = new ArrayList<>();
            return findUpMigrationPath(result, migrateUp, start, end);
        }
@ SuppressWarnings ( "WeakerAccess" ) @ Nullable public List < Migration > findMigrationPath ( int start , int end ) { if ( start == end ) { return Collections . emptyList ( ) ; } boolean migrateUp = end > start ; List < Migration > result = new ArrayList < > ( ) ; return findUpMigrationPath ( result , migrateUp , start , end ) ; }
Finds the list of migrations that should be run to move from {@code start} version to
 {@code end} version.
Finds the list of migrations that should be run to move from { @code start } version to { @code end } version .