IndexTreeMultiMap/2 - name clash: two methods same erasure as put(K,X) in AbstractMap

[crashdemons]

IndexTreeMultiMap: issue methods
public Collection<X> put(K key, Collection<X> values)
public Collection<X> put(K key, X value)

IndexTreeMultiMap2: issue methods
public C put(K key, C values)
public C put(K key, X value)

this code compiled OK on older Eclipse IDE, but on a new version with a Maven build, it fails.

Maven in Eclipse after clean compile:

[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap2.java:[885,18] name clash: class IndexTreeMultiMap2 has two methods with the same erasure, yet neither overrides the other
  first method:  put(K,C) in java.util.AbstractMap
  second method: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap2
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap2.java:[989,18] name clash: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap2 and put(K,C) in java.util.AbstractMap have the same erasure, yet neither overrides the other
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap.java:[916,30] name clash: class IndexTreeMultiMap has two methods with the same erasure, yet neither overrides the other
  first method:  put(K,java.util.Collection<X>) in java.util.AbstractMap
  second method: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap.java:[1015,30] name clash: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap and put(K,java.util.Collection<X>) in java.util.AbstractMap have the same erasure, yet neither overrides the other
[INFO] 4 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.720 s
[INFO] Finished at: 2020-09-29T19:35:18-05:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project EvLib: Compilation failure: Compilation failure: 
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap2.java:[885,18] name clash: class IndexTreeMultiMap2 has two methods with the same erasure, yet neither overrides the other
[ERROR]   first method:  put(K,C) in java.util.AbstractMap
[ERROR]   second method: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap2
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap2.java:[989,18] name clash: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap2 and put(K,C) in java.util.AbstractMap have the same erasure, yet neither overrides the other
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap.java:[916,30] name clash: class IndexTreeMultiMap has two methods with the same erasure, yet neither overrides the other
[ERROR]   first method:  put(K,java.util.Collection<X>) in java.util.AbstractMap
[ERROR]   second method: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap
[ERROR] /C:/Users/User/Documents/NetBeansProjects/EvLib/src/main/java/net/evmodder/EvLib/util/IndexTreeMultiMap.java:[1015,30] name clash: put(K,X) in net.evmodder.EvLib.util.IndexTreeMultiMap and put(K,java.util.Collection<X>) in java.util.AbstractMap have the same erasure, yet neither overrides the other
[ERROR] -> [Help 1]
[ERROR]