Frominor

[Bug] legend in Sankey

3

### Version 5.2.2 ### Link to Minimal Reproduction https://echarts.apache.org/examples/en/editor.html?code=CYQwLiAEC8kNoChKQN5OZAdiAtgUwC5IByEYgGnWQGNw8BzAewCcBPI4gRmPQF9LkaDFlyESAIwpVItMAxbsS3PgNTTs-DiG6qadJmw4AmHsn7ohGDWNIndM_Qo7Kzqy8msdxO6bPmGSAGZTSHNBdVEOailhPwNFLhDeBABdAG4EPGB6PABnGHgLaVzGAFdmahsyewhmHLAtH2EANxAAG1KxAFZ7OKcSahMVIuES8sqtGIxa-q07aVaOsUDexwDiahdQt2KyiptJGpA6vAaJJoxFzqIADlW5eKih1xGMMf3Jo5Oz4m8p5Cuy3u_gSmySO1Gewm53-kBmp0asMBRE4wMeA2Cw3CkPGBwuyHhP2i9mRkCMaP6Gy2yXSCAQjAADmAAJaMTAFSxtBh4TDAIgoMKQXJ4ZjMvL86RgVgMmy5ECYADWeFYsLaIFYZR-mDZeFhnhIuQVsLwOAZAAsQLlmbl-ZAAGaMailG0kEDAABWIEqmGoKu2dOEoAg9iyOVy9mFXOocmAAFlGMAbDhSm0WQyubDI3ho7a2szMHgAMpSrm26iMNosDjMLLEUL-l7IejMEDm5nUIiIYTuabSmzNsoM2HIUX0M1nABsAAZ7ATGUQZ9IaGbmW1gDXMJ2lxge8ICX3q9mwMO9wAvLnNPBtIgAFlne9yFpltrNeGZY7ORnJkAA7szgGAZpEIE37MEQXQNnuowlmIKD2qu14kAy-ZGpBUEEngAAeYAAMJsnImBnLu6Hnngl6IXe25QbkMG2nI2FRDo9r4YWzKnmInATuQ8FtIhvxqtQqHJOhGCCiJ9G4WydrvraDKMFaLJshw-ZWomdZiehbLUHmglEHapQ-op7IABQMgAlGoInCG0CoFHAtJWRgoZ5AAdA6zAAKJemaxnGZh3HMhZ0AAHyWY5GDMnakB-S5fRsDA0CwFSxAWTZLkMs6PmBRk4WhGZOXhTgrA4RazBgC5wDWgy4DUGaACC0aspgxnEeJB4kGAjD0PQXKFleR4niJQYgAAkryWFEDZ95DeAIAACrtcQzkhI5vD5VRokbcJe4pNI227bwaRAA ### Steps to Reproduce data = [ { name: 'a', category: 'Category 1' }, { name: 'b', category: 'Category 1' },...