const all_imported_specifiers = new Set(
    body
        .filter((el) => el.type === 'ImportDeclaration')
        .flatMap((import_thing) => {
            return import_thing.specifiers.map((specifier) => specifier.local.name);
        })
);

/**
 * @type {{type: 'Program', sourceType: 'module', body: typeof body}}
 */
const returned_ast = {
    type: 'Program',
    sourceType: 'module',
    body
};

walk(
    returned_ast,
    {},
    {
        Identifier(node, context) {
            if (!context.path.some((parent) => parent.type === 'ImportDeclaration')) {
                all_imported_specifiers.delete(node.name);
            }
        }
    }
);


returned_ast.body = returned_ast.body.map((statement) => {
    if (statement.type !== 'ImportDeclaration') return statement;
    const updated_specifiers = statement.specifiers
        .map((specifier) => {
            if (all_imported_specifiers.has(specifier.local.name)) {
                return null;
            }
            return specifier;
        })
        .filter(Boolean);
    return {
        ...statement,
        specifiers: updated_specifiers
    };
});

return returned_ast;

{
    type: "Identifier",
    name: "$.each",
}