Found the following HTML validation problems:
MeasureFairness.html:160:1 (MeasureFairness.Rd:121): Warning: <h5> anchor "Usage" already defined
MeasureFairness.html:166:1 (MeasureFairness.Rd:125): Warning: <h5> anchor "Arguments" already defined
MeasureFairnessComposite.html:137:1 (MeasureFairnessComposite.Rd:96): Warning: <h5> anchor "Usage" already defined
MeasureFairnessComposite.html:143:1 (MeasureFairnessComposite.Rd:100): Warning: <h5> anchor "Arguments" already defined
MeasureFairnessConstraint.html:151:1 (MeasureFairnessConstraint.Rd:110): Warning: <h5> anchor "Usage" already defined
MeasureFairnessConstraint.html:157:1 (MeasureFairnessConstraint.Rd:114): Warning: <h5> anchor "Arguments" already defined
MeasureSubgroup.html:131:1 (MeasureSubgroup.Rd:93): Warning: <h5> anchor "Usage" already defined
MeasureSubgroup.html:137:1 (MeasureSubgroup.Rd:97): Warning: <h5> anchor "Arguments" already defined
mlr_learners_classif.fairfgrrm.html:168:1 (mlr_learners_classif.fairfgrrm.Rd:119): Warning: <h5> anchor "Usage" already defined
mlr_learners_classif.fairzlrm.html:153:1 (mlr_learners_classif.fairzlrm.Rd:116): Warning: <h5> anchor "Usage" already defined
mlr_learners_regr.fairfrrm.html:165:1 (mlr_learners_regr.fairfrrm.Rd:122): Warning: <h5> anchor "Usage" already defined
mlr_learners_regr.fairnclm.html:161:1 (mlr_learners_regr.fairnclm.Rd:118): Warning: <h5> anchor "Usage" already defined
mlr_learners_regr.fairzlm.html:153:1 (mlr_learners_regr.fairzlm.Rd:116): Warning: <h5> anchor "Usage" already defined
mlr_measures_positive_probability.html:88:1 (mlr_measures_positive_probability.Rd:59): Warning: <h5> anchor "Usage" already defined
mlr_pipeops_equalized_odds.html:101:1 (mlr_pipeops_equalized_odds.Rd:107): Warning: <h3> anchor "Methods" already defined
mlr_pipeops_equalized_odds.html:171:1 (mlr_pipeops_equalized_odds.Rd:150): Warning: <h5> anchor "Usage" already defined
mlr_pipeops_equalized_odds.html:177:1 (mlr_pipeops_equalized_odds.Rd:154): Warning: <h5> anchor "Arguments" already defined
mlr_pipeops_explicit_pta.html:95:1 (mlr_pipeops_explicit_pta.Rd:76): Warning: <h3> anchor "Methods" already defined
mlr_pipeops_explicit_pta.html:165:1 (mlr_pipeops_explicit_pta.Rd:119): Warning: <h5> anchor "Usage" already defined
mlr_pipeops_explicit_pta.html:171:1 (mlr_pipeops_explicit_pta.Rd:123): Warning: <h5> anchor "Arguments" already defined
mlr_pipeops_reweighing.html:121:1 (mlr_pipeops_reweighing.Rd:114): Warning: <h3> anchor "Methods" already defined
mlr_pipeops_reweighing.html:201:1 (mlr_pipeops_reweighing.Rd:164): Warning: <h5> anchor "Usage" already defined
mlr_pipeops_reweighing.html:207:1 (mlr_pipeops_reweighing.Rd:168): Warning: <h5> anchor "Arguments" already defined
mlr_pipeops_reweighing.html:221:1 (mlr_pipeops_reweighing.Rd:177): Warning: <h3> anchor "Super-classes" already defined
mlr_pipeops_reweighing.html:227:1 (mlr_pipeops_reweighing.Rd:180): Warning: <h3> anchor "Methods" already defined
mlr_pipeops_reweighing.html:231:1 (mlr_pipeops_reweighing.Rd:181): Warning: <h4> anchor "Public-methods" already defined
mlr_pipeops_reweighing.html:258:1 (mlr_pipeops_reweighing.Rd:200): Warning: <h4> anchor "Method-+E2+80+98new+28+29+E2+80+99" already defined
mlr_pipeops_reweighing.html:262:1 (mlr_pipeops_reweighing.Rd:201): Warning: <h5> anchor "Usage" already defined
mlr_pipeops_reweighing.html:268:1 (mlr_pipeops_reweighing.Rd:205): Warning: <h5> anchor "Arguments" already defined
mlr_pipeops_reweighing.html:289:1 (mlr_pipeops_reweighing.Rd:220): Warning: <h4> anchor "Method-+E2+80+98clone+28+29+E2+80+99" already defined
mlr_pipeops_reweighing.html:295:1 (mlr_pipeops_reweighing.Rd:222): Warning: <h5> anchor "Usage" already defined
mlr_pipeops_reweighing.html:301:1 (mlr_pipeops_reweighing.Rd:226): Warning: <h5> anchor "Arguments" already defined