How to use the dgeni-packages/typescript/api-doc-types/ExportDoc.ExportDoc function in dgeni-packages

docs.forEach(doc => {
            if (!(doc instanceof ExportDoc.ExportDoc)) {
                return;
            }
            // Check for Dgeni documents that refer to the same TypeScript symbol. Those can be
            // considered as duplicates of the current document.
            const similarDocs = docs.filter(d => d.symbol === doc.symbol);
            if (similarDocs.length > 1) {
                // If there are multiple docs that refer to the same TypeScript symbol, but have a
                // different name than the resolved symbol, we can remove those documents, since they
                // are just aliasing an already existing export.
                similarDocs.filter(d => d.symbol.name !== d.name).forEach(d => duplicates.add(d));
                const docsWithSameName = similarDocs.filter(d => d.symbol.name === d.name);
                // If there are multiple docs that refer to the same TypeScript symbol and have
                // the same name, we need to remove all of those duplicates except one.
                if (docsWithSameName.length > 1) {
                    docsWithSameName.slice(1).forEach(d => duplicates.add(d));
                }