An African-American woman worked as an elevator construction “helper.” She aspired to become a “mechanic.” In order to become a mechanic and earn much higher pay, she had to successfully complete an apprenticeship. The apprenticeship program was overseen by a joint labor-management committee. Completion of the program involved working for three years in the industry, receiving classroom instruction, passing an exam, and obtaining on-the-job training from master mechanics. The woman accomplished the first three of these, but the male mechanics all refused to provide her with the necessary on-the-job training. She complained to her union, but was told that there was nothing that could be done. She sued. Has she been discriminated against? If so, who is liable? The employer? The union? Both?