Holder (Calcite Core 1.16.0 API)

```
public class Holder
extends MutableSingleRel
```
Implementation of MutableRel whose only purpose is to have a child. Used as the root of a tree.

Field Summary
- Fields inherited from class org.apache.calcite.rel.mutable.MutableSingleRel
  input
- Fields inherited from class org.apache.calcite.rel.mutable.MutableRel
  cluster, ordinalInParent, PAIRWISE_STRING_EQUIVALENCE, parent, rowType, STRING_EQUIVALENCE, type

Constructors
Modifier	Constructor and Description
`private`	`Holder(RelDataType rowType, MutableRel input)`

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`MutableRel`	`clone()`
`StringBuilder`	`digest(StringBuilder buf)`
`static Holder`	`of(MutableRel input)` Creates a Holder.

Methods inherited from class org.apache.calcite.rel.mutable.MutableSingleRel
childrenAccept, getInput, getInputs, setInput

Methods inherited from class org.apache.calcite.rel.mutable.MutableRel
deep, getParent, replaceInParent, toString

private Holder(RelDataType rowType,
               MutableRel input)

Class Holder