Question: actor starring as heimdall in the thor film series
[{'answer': 'Idris Elba', 'provenance': [{'wikipedia_id': '12673434', 'title': 'Thor (film)', 'start_paragraph_id': 1, 'start_character': 493, 'end_paragraph_id': 1, 'end_character': 503, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '12673434', 'title': 'Thor (film)', 'start_paragraph_id': 18, 'start_character': 0, 'end_paragraph_id': 18, 'end_character': 968, 'bleu_score': 0.988603523410381, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8508700711504617610}, 'section': 'Section::::Cast.\n'}]}]